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3 Background This chapter identifies the objective and intended audience of this report. It accentuates how critical reliable informa- tion about subsurface utilities is to airports and the risks that poor information poses to safety, operational efficiency, and infrastructure development costs. It also provides an intro- duction to subsurface utilities engineering (SUE) and how the processes it embodies help mitigate those risks. Finally, it summarizes the methodology for conducting this study and the contents of this report. The objective of this synthesis report is to describe cur- rent and effective practices within the airport industry of collecting, storing, and using subsurface utility informa- tion. The intended audience for this report includes airport operators, airport service providers, the FAA, and utilities/ infrastructure owners. Airports are typically served by a network of underground utilities, some of which may be operated independently. Unreliable and/or incomplete subsurface utility data can result in damage to these utilities during development or ren- ovation (Anspach 1998), which inevitably affects construct schedules, budget projects, and even safety (FAA 1993). The likelihood of unintentional utility damage during air- port development projects is high for two reasons. First, many airports operate somewhat autonomously from their surrounding jurisdictions. Their operating procedures are largely dictated by the FAA, which is focused on aviation safety, security, and efficiency and has no standards for under- ground utilities owned by airports or local entities. The FAA does have a standard for subsurface utility damage preven- tion (ANI1Q-QCW1342.1); however, it applies only to FAA projects (FAA 2004). There are mixed reports on whether this standard is being applied consistently among airports. Second, airports host a large volume of complex operations in a relatively small space. Supporting these operations with minimal above-ground hazard to aircraft operations requires a vast and complex network of underground utilities. In short, a large volume of buried utilities that support critical operations, combined with disparate procedures and a great deal of miss- ing data, leads to risks that need to be mitigated (FAA 1993). In 1994, the associate administrator for aviation safety initiated a study to review the causes and impacts of cable cuts from excavation, assess actions being taken to prevent disruptions, and provide information to FAA managers for use as a basis for decision making. The recommendations of that report were not implemented owing to FAA orga- nizational structure and funding constraints (Nguyen 2003). Because of the continuing problem of cable cuts, the director of National Airspace System (NAS) Implementation (ANI) initiated another study in November 2001 to revisit the issue and develop improvement practices to decrease cable cuts during ANI construction projects at airports. The ANI Advanced Implementation Team discovered the fol- lowing facts. All too often, utility damages can have catastrophic results. Even when not catastrophic, the results from damages can be significant. Being one of the many tenants at the airport, FAA owns vital underground utilities at airports. Disruptions to telecommunications or electrical power systems that support critical FAA facilities and services have a significant impact. These may include air traffic delays, increased air traffic work- load, and operational and personnel safety concerns. Multi- million dollars lawsuits are increasingly common. Traditional solutions have not reduced damages to an acceptable frequency. These solutions typically made the contractor responsible for utility protection during excavation, and encouraged or required some utility owners to mark their facilitiesâ locations on the ground surface just prior to construction. The ANI Team also discovered that the general engineering and construction indus- try has the same problem and is undertaking an increased effort to reduce underground utility damages during excavation. This effort includes the increased use of Subsurface Utility Engineer- ing (SUE), and the development of a new national engineering standard ASCE 38 (Nguyen, 2003). Other transportation sectors have also conducted exten- sive studies of the risks subsurface utilities can pose to safe and efficient operations and infrastructure. A large-scale study (FHWA 1999) characterized utility project risks on highways as follows: Project delays and extra costs resulting from: â¢ Unnecessary utility relocations based on incorrect loca- tion information â¢ Unexpected utilities found during construction â¢ Unexpected utility configurations â¢ Redesign of utility or structural project elements â¢ Unanticipated utility relocation construction â¢ Utility damage repair â¢ Utility damage environmental mitigation â¢ Utility damage pavement mitigation â¢ Utilities at unexpected depths chapter one IntroductIon
4 â¢ Utilities in poor condition that need replacement or repair â¢ Utility One-Call marks not matching up with construc- tion plan depictions. Initial project costs higher resulting from: â¢ Contractors pricing utility risk contingencies â¢ Investigation and processing of incomplete and inaccu- rate utility information Safety risks resulting from: â¢ Damaged utilities affecting safe vehicle operation controls, such as traffic signalization â¢ Traveler inconvenience resulting from closure of surrounding highways. The following news articles illustrate some of the poten- tial consequences of the risks posed by incomplete informa- tion about subsurface utilities at airports. new York times, January 10, 1995 Newark International Airport was crippled, then shut down, and air travel in the Eastern United States was seriously disrupted today after a construction crew driving piles for a new garage accidentally crushed high-voltage underground electrical cables serving the airportâs three passenger terminals. Several hundred of Newarkâs passenger flights were canceled and the travel plans of tens of thousands of people were ruined after the mishap cut off electricity to the three terminals at about 8:30 a.m. Some passengers flying from Europe to Newark ended up in Bangor, Me.; others took unexpected detours on domes- tic trips, landing at LaGuardia and Kennedy airports and being bused here to pick up cars and meet their families. At 5 p.m., the airportâs general manager, Benjamin DeCosta, ordered the airport, the nationâs ninth-busiest, shut until Tues- day morning as utility crews struggled into the night to install a 100-foot loop of cable to bypass the three damaged lines and restore power to the terminals. Minneapolis Star tribune, august 29, 2000 A severed cable temporarily disabled a landing system on two runways Monday morning at Minneapolis-St. Paul International Airport, delaying about 15 Northwest Airlines arrivals. Airport spokesmen said a construction crew accidentally cut a cable near the southeast end of the airportâs north parallel runway about 9 a.m. That led to a 50-minute interruption in operation of the two parallel runwaysâ instrument landing system, designed to guide arriving planes when visibility is low. colorado Springs airport Website news, January 11, 2007 At approximately 12:30 p.m., contractors working on the west side of the Colorado Springs Airport cut the primary fiber optics phone cable that serves the passenger terminal building. Airline and airport personnel have switched to back-up communications systems and it is anticipated that flight operations will continue on a normal schedule, with no impact on passengers. Mainte- nance crews are on site and estimate completion of the cable repair by 7:00 p.m. this evening. the orange county register, June 16, 2010 Commuters on the I-405 and 55 freeways came across some delays Wednesday morning after a gas line ruptured at a John Wayne Airport construction area. The main gas line to the airport terminal was damaged at about 7:30 a.m., said Jenny Wedge, an airport spokeswoman. It occurred at the construction site of the central utility plant, near a parking structure at the east end of the airport. Wedge said takeoffs and landings were not affected. While crews worked to shut off the gas leak, travelers were seen walking with their luggage along Michelson Drive. Baltimore Sun, February 10, 2004 A gas leak at BaltimoreâWashington International Airport tied up vehicle traffic yesterday afternoon and prompted the tempo- rary evacuation of three piers, airport officials said. Construction crews were working on part of the airportâs $1.8 billion expan- sion about 11:30 a.m. when they ruptured a gas line on the lower level outside the main terminal, said a spokeswoman for BWI. As the incidents above illustrate, utility disruptions pres- ent significant risk to airport operations, aircraft operations, and human safety. Identifying and developing strategies to mitigate them are an important part of an airport safety man- agement system (SMS). FAA Advisory Circular 150/5200-37 defines SMS as âthe formal, top-down business-like approach to managing safety risk. It includes systematic procedures, practices, and policies for the management of safety (includ- ing safety risk management, safety policy, safety assurance, and safety promotion)â (FAA 2007). The extent and complexity of the utility networks that can impact safety in and around an airport, the types of hazards or vulnerabilities that utilities present, and methods of address- ing them fall under the area of safety risk management. Air- ports can support the safety risk management process by accurately and comprehensively depicting the location of existing utilities, identifying the airport systems each serves, and providing important details that can help in assessing the level of risk and determining mitigation strategies. Dis- seminating information on subsurface utilities helps promote safety among contractors, airport maintenance staff, airline ground crews, and others that routinely come into contact with airport utilities infrastructure. Having effective methods of achieving accurate and com- prehensive subsurface utility information not only minimizes safety risks; it can limit their effect on construction project costs and schedules. Figure 1 illustrates the ability to control risks to program costs and various phases during a project development schedule. It is easier to control risks when accu- rate, comprehensive data are available early in the project development process (University of Texas 1986). However, airport project managers are often under pressure to deliver
5 a project at the lowest possible initial cost with little thought toward future operating and maintenance costs or utility safety issues. Developing procedures to avoid damaging utilities is not only good practice, it is a requirement. Airports that have scheduled passenger-carrying flights on aircraft with nine or more seats and unscheduled passenger-carrying flights with 31 or more seats must âProvide procedures, such as a review of all appropriate utility plans prior to construction, for avoiding damage to existing utilities, cables, wires, conduits, pipelines, or other underground facilitiesâ according to Part 139.341 of the Code of Federal Regulations (CFR 2011). A case might be made that the phrase âappropriate utility plansâ implies plans that are accurate and comprehensive. SUE was developed to incorporate the disparate, ineffi- cient, and unorganized methods of collecting and depicting utility data and establish practices to be carried out by reg- istered professionals with expertise in geophysics, survey- ing, and engineering. These professionals use their judgment to select appropriate basic and advanced technologies and then use those technologies to collect and depict the loca- tion of utility infrastructure and related details about it (i.e., attributes), as well as information about the quality of these data (i.e., metadata). SUE is widely recognized as a means of both managing and mitigating risks that subsurface utilities pose to the design and construction process (Anspach 2009). SUE is officially defined by the American Society of Civil Engineers as a branch of engineering practice that involves managing certain risks associated with utility mapping at appropriate quality levels (QLs), utility coordination (UC), utility relocation design and coordination, utility condition assessment, communication of utility data to concerned parties, utility relocation cost estimates, implementation of utility accommodation policies, and utility design (ASCE 2002). An important duty of the subsurface utility engineer is effective coordination, communication, and cooperation between stakeholders, including utilities, One-Call centers, public agencies, consultants, construction contractors, and project owners (AASHTO/FHWA 2002). The use of SUE in other transportation sectors consistently shows a significant return on investment (ROI), with the most recent study by Penn State University documenting a 2200% ROI over traditional means and methods of collecting, depict- ing, and using utility information (Singha 2007). Said another way, every $1 spent in using appropriate geophysics to reli- ably identify utilities early in the project delivery process cut costs by $22 in reduced test excavations, redesign costs, proj- ect delays, contractor change orders, bid prices, unnecessary utility relocations, and utility and environmental repairs. In other studies that encompassed more than 100 capi- tal improvement projects of various sizes and complexities, totaling well in excess of $1 billion worth of design and construction costs, ROI was positive in all but three proj- ects. This led Purdue University to conclude that the use of SUE, in particular the use of geophysics as a tool for utility mapping, should be used systemically for highway projects. These studies included: â¢ Virginia Department of Transportation: 700% ROI (Scott 1996) â¢ Maryland State Highway Administration: 1800% ROI (FHWA 1995) Figure 1 Ability to influence construction costs as a function of the project development process timeline (university of Texas 1986).
6 â¢ Purdue University: 462% ROI (FHWA 1999) â¢ University of Toronto: 341% ROI (Osman 2005). The typical way that utility information is deemed reli- able is by knowing its origin, the qualifications of the per- sons creating it, the technology they used, and the amount of trust placed in these persons. The result is a massive amount of metadata, or information specifically about the utilities data that is required for a user to ascertain reliability. The ASCEâs Standard Guidelines for the Collection and Depic- tion of Existing Subsurface Utility Data, CI/ASCE 38-02, simplifies this process by defining a utility quality level (QL) attribute that incorporates origin, qualifications, technology, and trust/accountability. QL is broken down into the follow- ing four levels: â¢ Utility quality level A (QLA)âInformation obtained by the actual exposure (or verification of previously exposed and surveyed utilities) and subsequent direct measurement of subsurface utilities, usually at a spe- cific point. â¢ Utility quality level B (QLB)âInformation obtained through the application of appropriate surface geophys- ical methods to infer the existence and approximate horizontal position of subsurface utilities. QLB data should be reproducible by surface geophysics at any point of their depiction. The horizontal locations are surveyed to the horizontal positional accuracy require- ments of the project or any required statute. â¢ Utility quality level C (QLC)âInformation obtained by surveying and plotting visible utility features and by using professional judgment in correlating this infor- mation to quality level D information. â¢ Utility quality level D (QLD)âInformation derived from existing records or oral recollections. audIence This report is primarily written for airport design and construction project managers and their counterparts in consulting organizations. These individuals are the pri- mary parties who will decide if and how SUE practices and principles are incorporated into the projects they man- age and used to manage underground utility risks. Airport engineers, computer aided design and drafting (CADD)/ geographic information system (GIS) technicians, and sur- veyors can also benefit by understanding the technologies, practices, and policies that guide their work. Although the report is written for airport administrators and their con- sultants, FAA managers and staff who are involved with projects that install utilities will also find the information in this report helpful. This report can be useful for airports of any size. While larger airports often embark on larger construction projects and have larger budgets for SUE activities, smaller airports must also manage utility networks, incorporate utilities into planning and design projects, and be aware of possible utility conflicts during construction. MethodologY This study was carried out in three phases. First, a search for existing relevant literature was conducted and the result- ing documents were reviewed for information about the state of the technology, art, or practice. Second, phone interviews were carried out with a variety of airport administrators and their consultants. A questionnaire was designed to solicit information about current practice at airports and was used to guide these interviews. Third, an e-mail survey was con- ducted of firms that have provided SUE services to airports. The results were combined with information identified dur- ing other studies being conducted by the investigators, as well as their experience providing SUE services to airports. All of the information gathered was synthesized into this report, a draft of which was reviewed by a panel of experts, before this final report was produced. This methodology is described in more detail here. literature Search A literature search was undertaken to identify documents in the public domain that relate to subsurface utilities and airports. The literature search made use of Transportation Research International Documentation (TRID) and the Inter- net by means of commercial search engines. Keywords placed in the TRID search engine returned only 12 results, none more recent than 2004, and after review of the abstracts, only two pertained to this topic. Removing any keyword reference to aviation or airports produced an additional 275 results, some of which were relevant regardless of transportation or indus- try sector. Internet searches were performed with various combi- nations of keywords such as âutilities,â âsubsurface util- ity engineering,â âSUE,â âairport,â and âFAA,â with the names of each type of utility found at airports (i.e., âfuel,â âwater,â âstorm,â etc.) as well as with specific types of studies typically carried out by airports (i.e., âstorm water pollution prevention planâ). This produced 1,700 results. Technical paper abstracts were reviewed for applicabil- ity. Seven were found that had not already been identified through other means. The vast majority of the documents were SUE consultant websites or articles that mentioned SUE and airports in the same document, but had no useful information for this study. To complement electronic searches for documents and phone interviews, e-mails were sent to a sampling of airport industry consultants. Specifically, members of the Transpor-
7 tation Research Boardâs (TRBâs) Airport GIS Subcommittee and attendees of American Association of Airport Execu- tives (AAAE) conferences held over the last 14 years were contacted. They were asked for copies of or references to written procedures, standards, request for proposals, or other material that related to utilities data at airports. Finally, refer- ences furnished by this studyâs expert task group, and litera- ture and documents already in the possession of this studyâs investigators, were also reviewed and are contained in the References. Phone Interviews Sixteen airports were identified at the 2011 AAAE GIS con- ference as having recent capital improvement projects with utility involvement. All 16 agreed to be interviewed and subsequent telephone interviews were conducted. Two air- ports were outside the U.S. Of the 16, eight are considered large-hub airports; that is, airports handling more than 1% of the nationâs annual passenger boardings. Interviews lasted approximately 90 minutes and were structured from a ques- tionnaire that was sent to the airports before the interview so that respondents could internally seek the answers from different departments within their organizations. The ques- tionnaire was intended as a guide to facilitate discussion. A blank copy of the questionnaire is included in Appendix A. The answers have been aggregated to maintain confidential- ity of interviewees and are included in the body of this report. Airport interviewees suggested other sources of informa- tion, and as a result, informal interviews were also conducted with several large consulting engineering firms, FAA repre- sentatives, software and hardware vendors that supply the airport and/or public utility industries, and energy industry representatives. e-Mail Survey A questionnaire was developed and sent to 15 major SUE providers whose websites indicated they had experience with mapping utilities at airports. Ten firms responded, with util- ity mapping experience covering 44 airports. The 44 airports covered included eight for which interviews were conducted. The questionnaire provided both confirmation and differing perspectives of the procedures at these eight airports. Figure 2 illustrates the geographic extent of North Ameri- can airports for which information was gathered. In addition, two Western European airport authorities were interviewed. Parallel Study In addition to the interviews carried out for this project, investigators were concurrently carrying out similar research in support of other federally funded studies. Although the objectives of these studies differed from the review con- ducted for this project, some of the information gathered in these other studies was related to subsurface utility engineer- ing at airports and was therefore taken into account. These studies include the Strategic Highway Research Program Projects R-01A, R-01B, and R-01C. docuMent organIzatIon This document has been organized into a Summary, seven chapters, and four appendices. â¢ Chapter one provides an introduction stating the objectives and intended audience of this report. It identifies the problem that this report is intended to help address and identifies processes airports have used to effectively overcome it. This introduction also describes the methodology used during this study and provides an overview of the organization of this document. â¢ Chapter two details the existing state of the technology (SOT). It reviews current geophysical tools for imaging utilities, survey tools for both positioning the geophysi- cal tools or for creating as-builts of exposed utilities, information storage and retrieval methods, and technol- ogy integration where the lines are blurred. â¢ Chapter three deals with the state of the art (SOA). It explains how property and project owners who rou- tinely contend with utility issues integrate the available technology into a system that reduces utility risk during projects, maintenance, and operations. â¢ Chapter four reviews the results of the interviews and surveys. It explains how airports in general are deal- ing with utility data management. It can be used as a comparison between what can be done, as described in chapters two and three, and what is being done. It is a Figure 2 Distribution of airports for which information on this study was collected.
8 â¢ Chapter six looks at research in progress. It identi- fies any current research that is related to the topics addressed in this study. The purpose of this is twofold: first, to identify areas where additional information will soon be available; second, to provide suggestions that may help influence these other studies so that they pro- vide additional benefit to the intended audience of this study. â¢ Chapter seven summarizes the report conclusions and identifies areas for further research. snapshot of the state of the practice (SOP). By request, the identity of individual airports in this section is not revealed. â¢ Chapter five highlights what individual airports, their consultants, and SUE providers believe are effective practices being used by at least some airports and that could be considered for use by a broader audience. While at first glance this may appear like integration between SOT and SOA, it takes the perspective of users and providers into account.