The contractors' task is frequently made tougher by low bid contracting mechanisms currently in favor by most project owners.  Invariably, the contractor and owner end up in arbitration or litigation over the problems caused by unknown or incorrectly depicted utilities, further increasing project costs.  The courts are beginning to recognize that contractors are unfairly put at risk in this practice (See, I.A. Construction Corporation v. Department of Transportation, 591 A.2 1146, Pa.Cmwlth, 1991). The rule of law developed in I.A. Construction Corporation places responsibility for the depiction of subsurface utilities squarely on the shoulders of owners.² 

In many cases, a project owner is funded by the taxpayer or ratepayer.  There is little incentive, and sometimes a disincentive, to employ strategies that will lower costs.  This is especially true in cases where current practices have a long standing history.  The costs of "doing business" are passed on to the public.  Sometimes these costs are lives.

SUBSURFACE UTILITY ENGINEERING

A new engineering technology is emerging that combines the traditional disciplines of geophysics, surveying, and civil engineering in a practice called Subsurface Utility Engineering (SUE).  SUE provides data on existing utilities and other manmade subsurface structures at appropriate times in the design process. The subsurface utility engineer takes responsibility for the accuracy and completeness of the utility information on the plans and has specialized professional liability insurance to support his services.

In order to understand SUE, it is important to first define the quality levels of utility information that are available to the design engineer, constructor, and project owner.  The generally accepted definitions are as follows.^3,4

 Quality Level "D" - Existing Records:  Results from review of available records.  Gives overall "feel" for congestion of utilities, but is highly limited in terms of comprehensiveness and accuracy.

 Quality Level "C" - Surface Visible Feature Survey:  QL "D" information for existing records is augmented using surface visible feature survey and digitizing data into CADD.  The danger here is that much of the data is "digitized fiction."  It is not unusual to find a 15-30% error and omission rate in QL "C" information.

 Quality Level "B" - Designating:  Two-dimensional horizontal mapping.  This information is obtained through the use of surface geophysical methods.  It is highly useful for design basis information for conceptual design, and for proceeding prudently to QL "A".  It should not be used for design basis vertical information, or where exacting horizontal tolerances are expected.

 Quality Level "A" - Locating:  Three-dimensional horizontal and vertical mapping.  This information is obtained through vacuum excavation of test holes at points of conflict.  This is the highest level of accuracy of subsurface utility engineering data.  It provides horizontal and vertical design basis information for engineering, construction, maintenance, remediation, condition assessment, and related efforts.  

Subsurface utility engineering departs from traditional engineering practice in the Designating (QL "B") component.  This component consists of applying surface geophysical methods to the project area, interpreting the results in the field, marking these designations on the ground surface, and surveying the designations to permanent project control.  The final work product undergoes a rigorous professional review both in the field and in the office.  Existing utility owner information is correlated to the work product and discrepancies are either resolved or further recommendations are forwarded to the client.  Deliverables are "sealed" by an appropriately registered professional.

Unlike utility owners (or their contractors) marking their facilities at time of construction, the SUE practitioner has available many surface geophysical methods and equipment  (See Table 1).  Method selection is one of the first steps that is crucial to a cost-effective accomplishment of the mission.  Utilities and other subsurface structures are composed of differing materials, sizes, and methods of enjoinment.  They are emplaced at varying depths.  Their surrounding environments can change drastically from point to point.  Surface features such as water, buildings, scrap metal, etc., vary from site to site.  Utility corridors are often highly congested with many different types of utilities.  All these factors combine to defeat the application of any one surface geophysical method from identifying underground structures.  Therefore, an integrated approach of different methods is necessary.

Radiofrequency Electromagnetics - ELF, VLF, LF ranges	Inexpensive and highly useful for metallic utilities, or utilities that can be accessed and a conductor or transmitter inserted into them.
Magnetics - Flux gate	Inexpensive and highly useful for utilities or their appurtenances that exhibit a strong magnetic field at the ground surface.
Elastic wave introduction into a non-compressible fluid.	Inexpensive and moderately useful for water lines with sufficient access points (typically fire hydrants) and low ambient noise.
Terrain Conductivity	Moderately inexpensive and useful in non-utility congested areas, or areas of high ambient conductivity.  Most useful for tank and drum detection.
Impulse radar (Ground Penetrating Radar)	Moderately expensive and highly interpretative.  Useless in areas of high conductivity such as marine clays, or for small utility targets.
Seismic Reflection and Refraction	Expensive and highly interpretative. Usefulness under field conditions extremely limited due to signal/noise ratio problems.
Thermal Imagery	Moderately expensive and interpretative.  Sometimes useful for poorly insulated steam systems or other high heat-flux systems.
Radioisotope tracing	Moderately inexpensive to highly expensive.  Useful for utilities already impregnated with radioactive isotopes.
Microgravitational	Expensive. Limited to identifying utilities of great mass differential from their surrounding environment.

Table 1.  Available surface geophysical methods for subsurface utility characterization

If a project had an unlimited budget, perhaps all available methods would be used by the SUE practitioner.  However, this is a luxury rarely allowed or prudent.  Through a combination of

In some cases, utilities exist in the subsurface environment for which no reasonable combination of surface geophysical methods will provide interpretable results.  Additionally, the amount of extra cost to identify some utilities through these methods can be counterproductive to the project budget.  Therefore, typical cost-effective scopes of work for a majority of projects limit techniques to ELF, VLF, LF, magnetics, and elastic wave propagation through water lines, with additional surface geophysical techniques recommended only on a case specific basis.

This Quality Level "B" data is usually sufficient to accomplish preliminary engineering goals.  Decisions can be made on where to place storm drainage systems, traffic management systems, etc., in order to avoid conflicts with existing utilities.  Slight adjustments in design "footprints" can produce real cost savings by eliminating wide-scale utility relocations. However, potential conflicts will still occur in the complex underground setting.

Contrary to many manufacturers' claims, depth determinations from the surface are not reliable.  Neither is the other available data that the design engineer typically uses to produce a reliable design.  As design proceeds to more advanced stages of refinement, the engineer needs data about precise width, location and horizontal extent of the utility system, elevation, configuration of non-encased multiple ducts, utility size, utility condition and material type, surrounding environmental conditions, etc.  Such data cannot be obtained by simply applying the technologies outlined in Table 1 (QL "B").  Therefore, as a further refinement to the previous designating process to resolve ambiguities and to obtain more precise data on utilities where necessary, a physical exposure of the utility system at the appropriate location must be made.  This process is termed Locating and represents Quality Level "A" data. 

Traditional excavation methods using backhoes or other heavy equipment, and even hand shovels or "post-hole" diggers present the real possibility of damage to the utility being exposed.  Utility systems such as fiber optic cables, terra-cotta or tile ducts, and small gauge command and control cables can be easily cut.  Corroded metallic systems, spalled concrete pipe, and asbestos cement pipes can be quite fragile.  Even steel systems in good condition can be unknowingly compromised when their protective coatings and wrappings are nicked or gouged, creating localized corrosion cells. 

Air/vacuum excavation systems eliminate the above problems.  Additionally, the work area/surface cut is quite small, often measuring no more than eight inches square as compared to a typical three foot by five foot backhoe pit.  Dump truck support vehicles for both dirt hauling and backfill material are unnecessary, reducing the imposition on existing traffic flow.  The small excavation that exposes the utility system at the precise spot where data is necessary does not require sheeting or shoring.  Dewatering of high water tables is easily accomplished when necessary. Backfill and proper compaction of the excavation and paving repair is a simple and inexpensive task. Traffic control and worker safety is better in this small confined work area.  The air/vacuum system is a better way to dig a hole, but the real value comes in the data collected from the exposed utility. 

By knowing precisely where a utility is positioned in three dimensions at the beginning of the final design process, the designer can make prudent decisions.  Small adjustments in design elevations or horizontal locations of new structures might eliminate a utility adjustment. Cut and fill areas might be altered to accommodate the existing utilities while still accomplishing the design mission.  Sometimes utility relocations are necessary.  By knowing the size, material, and location of the existing utility, the designer can produce realistic cost estimates for moving the utility out of the way of construction.  By utilizing the previous Designating data, empty corridors for the utility relocations can be quickly identified. 

The physical location of the utility is not the only useful data supplied to the designer during the Locating stage.  Soil conditions, groundwater elevations, possible soil contamination, paving thicknesses and type, condition of the utility, and the depth to rock under the utility trench are all factors that may affect design decisions.  When this comprehensive data, along with construction safeguards such as permanent field markers, are made available to the constructors at the pre-bid meeting, significant reductions in bid prices are realized.⁵ 

The data as discussed above is collected by field engineers, surveyed to permanent survey control, and formatted for easy reference for both the designer and the constructor.  As in the Designating process, rigorous quality control processes are employed.  The data is "sealed" by an appropriately registered professional and insured against errors and/or omissions.

While the utility is exposed, an assessment of its condition can be made.  Nondestructive testing techniques to meet the needs of the project owner, project designer, and utility owner are discussed prior to excavation.  Typical techniques utilized are ultrasonic pipe wall thickness measurements, pipe-to-soil potential measurements, current flow measurements, acoustic emission measurements, temperature gradient measurements, and visual examination by camera insertion.  This information is useful for the utility owner, who may decide to replace a system before broadscale failure.  The contractor also benefits from a record of the utility condition before construction begins, as he can make the proper excavation and utility protection choices.⁶ 

ONE-CALL VS. SUBSURFACE UTILITY ENGINEERING

Let's review the most prevalent damage prevention program, excavation notification systems and subsequent procedures (one-call), and illustrate the significant enhancements that result from SUE.   

one-call: Without a single responsible party to make sure all utility information is correctly identified, many errors can and do result.  For instance, the gas company may mark the water line as a gas line.  The water company, in most likelihood, will not mark the gas line or in many cases even notify the gas company that there may be a mistake in the field.  Abandoned utilities may be assumed to be the active ones.  There are a lot of permutations of errors available here. Even so-called "multiple party locators" won't solve this problem unless all utility owners, known or unknown, active or not, participate. 

SUE: The SUE engineer assumes responsibility for the comprehensive and accurate depiction of all utilities on a project.  Strict quality assurance controls are in place with several layers of review.  All information is "sealed" against errors or omissions. 

one-call: Full participation by all utility owners may never be achieved.  Many utility owners with facilities still in the ground are disbanded.  Examples include industrial plant facilities, old railroad owners, etc.  These "unknown" utilities will never be addressed by a one-call system. Sometimes these utilities are still filled with environmentally damaging products or hazardous materials.  If the contractor is lucky enough not to damage it during construction, he may proceed recklessly thinking it's harmless, or proceed with extreme caution.  Either way the unanticipated costs may be significant.

SUE: All "unknown" utilities reasonably capable of being found are identified before construction and reviewed during the pre-construction meeting. 

one-call: Abandoned utilities are often ignored.  Many times this creates danger when an abandoned utility is uncovered and assumed to be the active one.  Further excavation in the area is assumed "safe" and the active line is hit.

SUE: Abandoned and active utilities are identified and reviewed during the pre-construction meeting. 

one-call: A very short time is available (48-72 hours) to receive notification and act on it in the field.  This time pressure often results in errors.  Certainly there is little time to initiate proper quality control procedures. 

SUE: SUE is completed during the design process of a project. 

one-call: Data is lost the minute construction obliterates the marks.

SUE: All data is referenced to survey control and is retained in a CADD/GIS system.  Additionally, as part of the QL "A" process at points of actual conflict with utilities, permanent markers are put in the backfill from the ground surface to the utility.  Conflicts can be quickly reconstructed by referencing the conflict with existing topological features identified and measured during the QL "A" process.  

one-call: Field technicians are mostly hired on the basis of low bids, with little attention to education, training, and available equipment.  Often "gypsies" who "buy" jobs will close shop when damages occur.

SUE: SUE is a professional service requiring adherence to strict standards.  A SUE firm is accountable to its insurance company and the appropriate licensing agency. 

one-call: Mix-ups or miscommunications in ticket locations often occur.

SUE: Accurate utility information is presented on the original construction drawings. 

one-call: Utilities are essentially ignored until just prior to construction.

SUE: Utilities are investigated in a professional manner from project planning through the design process.  All utility conflicts have been identified to the project owner, the engineer, and the utility owner before construction bidding occurs.  Many times, utilities are relocated away from construction before it begins. 

one-call: Constructor has only paint or other surface marks as a representation of some of the underground utilities.

SUE: Constructor has permanent surface and subsurface markers, plan sheets, and formatted information sheets with comprehensive and accurate representations of underground utilities. 

COST SAVINGS

The advantages of SUE go beyond that of decreasing the risks of damage to utilities during construction.  Tremendous cost savings to the public taxpayer and ratepayer also accrue on projects utilizing SUE.  The basic areas of project expenditures are approximated as follows.⁷  

Administrative Costs                    20%

Engineering Costs                       10%

Construction Costs                      45%              

Cost "Overruns"                          15%

Utility Relocation Costs                10%

Cost savings come in many forms.  The total savings on a typical project may range from 10% to 15% (compared with costs from a project not supported by professional SUE).⁸  These savings result from the following approximate reductions in cost percentages as identified by the Society of American Value Engineers and the Federal Highway Administration.

Administrative (1/10th of 20%) 2%.  Projects completed up to 20% faster (Virginia Department of Transportation study) allows financing to be paid quicker.  Insurance and bonding costs may be less.  Administration of change orders is lessened.            

Engineering (1/20th of 10%) 1/2%.  SUE techniques save time, therefore expense, by employing direct digital incorporation of utility data from survey into CADD files.

Utility Relocation (1/2 of 10%) 5%.  Designers take comprehensive accurate utility information into consideration during the design of a project.  Minor changes of design "footprint" or elevation data on paper eliminates wholescale utility relocations before construction.

Construction (1/20 of 45%) 2.25%.  Construction bids are lowered because of fewer utility conflicts and an increased assurance of correct data.  Liability for identification of utilities is borne by the SUE firm, not the constructor.

Cost Overruns (1/3 of 15%) 5%.  Contractor delay claims are reduced (Florida State Department of Transportation).  Engineering rework is reduced.  Utility damages are reduced.

CASE SUMMARIES

FHWA SAVINGS

A Federal Highway Administration (FHWA) official stated (during the 1990 National Highway/Utility Conference) that applying SUE nation-wide would conservatively save the FHWA $100 Million annually.

VIRGINIA SUE PILOT PROJECT

Virginia Governor Gerald L. Baliles convened a meeting in Richmond to identify ways to accelerate Virginia's Highway program.  A key part of the meeting was a presentation reporting the value of subsurface utility engineering services on a Rte 1 highway project in Crystal City.  Mr. J.C. Carr, Virginia State Utility Engineer, stated that VDOT saved over $1 million in redesign and utility

REDUCED UTILITY RELOCATION COSTS

A project performed in the City of Richmond for the Virginia Department of Transportation was analyzed by VDOT for cost-effectiveness.  State Utility Engineer Richard Bennett stated "We feel like we eliminated over $700,000 worth of utility conflicts, and the (cost of SUE) was less than $100,000.  We can't imagine going back and doing a project without having this information available to us."

REDUCED CONSTRUCTION DELAY CLAIMS

The Florida Department of Transportation analyzed the use of SUE on large projects in Tallahassee and Miami.  Paul Kaczorowski, FDOT State Utility Engineer, stated that FDOT

REDUCED PROJECT COMPLETION TIME

The Virginia Department of Transportation credits SUE with reducing Design and construction time on highway projects by as much as 20%.  Jack Hodge, Chief Engineer for VDOT, stated "In 1984 the Virginia DOT implemented an extensive SUE program and it is an integral part of the complete engineering design of a project.  It allows us to locate utilities, find the conflicts, and design around them.  This program is a vital part of our mandate to design and construct projects in a timely fashion."

REDUCED CONSTRUCTION BIDS

Columbus Southern Power Company completed design and construction of an underground 138 kV pipe type transmission line through a congested urban setting at lower cost, reduced risk, and on schedule by combining conventional surveying, aerial photography, innovative construction techniques, and subsurface utility engineering (SUE) in its design.  Past dependence on old utility records to establish potential pipeline construction conflicts had resulted in construction delays, extra costs and construction damages.  The increased quality of the utility information presented at the pre-bid meeting increased the bidders' confidence in the construction plans, resulting in a bid of $997,065, which was $400,000 less than anticipated. There were no change orders as a result of utilities not correctly depicted on the plans.  Additionally, there were no utility relocations or damages on this project.   This project in Columbus, Ohio illustrated how the combination of innovative construction techniques and SUE lowered contractors' bids, eliminated contingency allowances for unknown or misrepresented underground utilities, decreased the construction and design time, and allowed the owner to realize significant project savings.

AIRPORT CADD SYSTEMS/UTILITIES

A major U.S. airport paid over $1 million dollars to digitize utilities from records into a CADD/GIS system for future construction projects.  In a study comparing SUE QL "B" (designating) to QL "C" (records and topo survey) on a 20 acre section of that airport, QL "C" failed to identify 20% of the utilities at all, and failed to place over 50% of the utilities within 5 feet horizontally of where they actually were found. The costs of SUE were extrapolated to be less than $500,000 to map the entire airport to QL "B" standards.

FAA "SPECIAL REVIEW"

In 1993, the Federal Aviation Administration released a report after review of data from the FAA's National Airspace Performance Reporting System (NAPRS) revealed that during a two-year period, 1,444 equipment outages or disruptions resulted from 590 cable cuts nationwide.⁹  An FAA report to the Congress for the period August 1990 through August 1991 identified 114 disruptions as major telecommunications outages; that is, those outages which have a "significant operational impact, including air traffic delays, increased air traffic workload, and safety concerns."¹⁰  The FAA's special review recommended that subsurface utility engineering technologies should be employed to minimize the possibility of cable cuts. 

THE COST OF NOT USING SUE

The "Great Chicago Flood of 1992" caused over $1 billion in damages.  These damages could have been prevented with the proper application of SUE.  The cost of applying SUE was estimated at less than $2,000.

ACCEPTANCE OF SUE

 According to the FHWA, 14 states are now using SUE on a regular basis for their highway construction projects.  The FHWA has a stated goal that they wish to see all state DOTs using SUE by the year 2000.  So far, the FHWA is the primary governmental agency advocate for SUE.  However, there is a growing list of supporters in other areas. Some local agencies, such as Fairfax County, VA, require SUE on public projects.

There is growing congressional support.  Congressman Thomas J. Bliley, 3rd District, Virginia recently stated "I believe subsurface utility engineering can improve safety, protect the environment, and save billions of dollars on those projects that require excavation in areas where underground systems and structures may exist.  Requiring all agencies involved in an excavation to determine the three-dimensional location of underground structures prior to design appears to be an extremely prudent policy, and deserves comprehensive consideration.  Furthermore, I firmly believe that all agencies should use the best, most cost-effective technologies available."¹¹

However much SUE makes sense as a damage prevention and cost containment vehicle, there are still major obstacles standing in the way.  Most of these obstacles have their roots in the conflicting roles of engineers, utility owners, and constructors.  These roles conflict mostly due to ineffective incentives granted by governmental agencies.

OBSTACLES TO SUE

Let's examine the engineers', utility owners', and constructors'  typical positions, both their on-the-record and off-the-record responses, on the use of subsurface utility engineering.

ENGINEERS

ON-THE-RECORD:  Subsurface utility engineering is expensive and is an expense that must be paid before the first "draw" is typically available from the project owner.  SUE is not needed because project engineers have always shown the location of underground utilities on the site plan as a part of the engineering fee.  Project engineers often show utility locations in the project CADD system.  SUE might slow down the design time and require more time and coordination by the project engineer, thereby costing the project owner money that the contractor would otherwise absorb during construction.

OFF-THE-RECORD:  SUE is great if you are the project owner.  SUE helps assure the project owner that there will be no underground utility surprises that cause construction delay claims, change orders, unnecessary utility relocation charges, utility damage costs, engineering change orders or related extras for the constructors and project engineers.  In these days of tight negotiations for engineering services, engineers make money on the change orders that arise in complex projects.  Underground utility problems are usually discovered at the last minute, and are unforeseen.  Consequently, engineers profit from utility problems.  If there were a standard requirement that all projects use SUE, we would gladly use SUE in competitive negotiations for projects.  Until SUE becomes a standard requirement, however, advanced engineering firms can lose competitions when they tell the project owner to spend what is traditionally perceived to be construction or contingency money upfront.

FACTS:  By taking a small percentage of the money budgeted for contingencies and investing it prior to design with a SUE firm, the project owner can generally reduce the total design and construction budget by about 10%.  SUE is usually completed in less time than it takes for traditional engineering processes to research and digitize utility information.  Using traditional engineering methods, this utility information always comes with a disclaimer of reliability and a recommendation for the contractor to coordinate, verify and manage underground utility information at the time of construction.

UTILITY OWNERS

ON-THE-RECORD:  SUE is an expensive way to provide utility location information that we provide to all engineers for free.  SUE is another gimmick to charge unaware engineers and project owners for an unnecessary service.  We provide free location services to contractors at the time of construction.

OFF-THE-RECORD:  In the past, technology did not exist to provide three-dimensional utility data.  Now that this technology exists, we as a utility industry don't want to provide the same level of service every time someone asks.  Even if we could charge for the service (which we cannot), we do not want to be liable for the risk of providing bad data.  Therefore, we will quietly support the SUE profession.  The appropriate state agency may eventually seek to require us to make available the same level of service as SUE.  We can't have that.  If we see it happening, we would fight to maintain the status quo.

FACTS:  Utility companies, as they are currently set up, cannot provide three dimensional data.  First, they are union operations and have few, if any, professional geologists, engineers, or land surveyors on staff.  Second, utility companies are not efficient enough to manage professional engineering services.  This is why they almost always use consultants to do technical design and evaluation.  Third, consumers can't afford, nor should they be expected to pay for, utility information provided for the private benefit of project owners.  In the private sector, developers build to generate a profit for themselves, not utility consumers.  In the public sector, government agencies

often own the rights-of-way, and can simply require utilities to relocate the existing utilities if it conflicts with the new design.  Fortunately, more agencies are realizing that the ratepayer and taxpayer are the same person.

CONSTRUCTORS

ON-THE-RECORD:  We need better data in order to meet our schedules, manage project risks, reduce change orders and protect our people and equipment.

OFF-THE-RECORD:  We make a lot of money from change orders caused by poor utility data.  Our prime concern is not hurting our employees, but when you get past that issue, we don't get hurt when we get held up by unknown utilities and the problems they create.

FACTS:  Constructors, like engineers, will not argue with their project owners to spend the money upfront for SUE in order to stop engineering and contractor change orders.  

SUMMARY

Competent damage prevention strategies must begin early in the project planning process.  The existing reliance upon one-call systems, at time of construction, to be the major and often only damage prevention tool, is outdated.  Subsurface utility engineering is a proven technology that provides significantly enhanced damage prevention capabilities, while reducing costs to the public.  The benefits of SUE begin in the project planning stage and accrue throughout the life of the project. SUE obstacles include public agency bureaucracy, budgetary division of project funds, and contracting mechanisms.  Currently, everyone except the project funder, which is usually the tax and ratepayer, benefits from the troubles caused by inaccurate utility data on a project.  However, enlightened agencies such as the FHWA are beginning to recognize this and are encouraging new technologies such as SUE for the public good.