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An Industrial Plant (Plant) is typically associated with various types of processes such as oil, gas, wastewater, potable water, recycled wa-ter, and/or electricity generation. Within a Plant, there are buried utili-ties associated with multiple systems that support various processes. The number of different utility systems inside a Plant can range from a few to many dozen; portions of which are usually buried. Most Plants store their buried utility information on multiple sets of as-built draw-ings, some of which can be decades old and difficult to read. Further-more, for some areas there may be no drawings; the information for what is buried residing in the minds of long-serving employees who are soon to retire. Once they retire this knowledge goes with them and is likely gone forever. The need for establishing a program for manag-ing buried utilities in a Plant is greater than ever. This article outlines how to establish a Plant-based subsurface utilities damage prevention program and the advantages achieved by implementing such a program, highlighted by using the example of the San Jose/Santa Clara Regional Wastewater Facility (RWF). The RWF is a large wastewater treatment plant that resides on five square miles of property. It treats the wastewater for most of California’s Silicon Valley. Built in 1956, like most Plants, aging infrastructure and knowledge retention are major concerns. Poor documentation of buried utilities led to project delays ranging from hours to days, in addition to cost overruns from tens of thousands to hundreds of thousands of dollars. Furthermore, the risk of injury and/or catastrophic failure resulting from hitting poorly document-ed utilities was substantially increased. As construction increased these circumstances became intolerable to a degree where something had to be done. The answer was to develop a subsurface utilities damage prevention program. The steps in establishing such a pro-gram involved the following:• Assessment of technology and staffing needs• Adoption of Subsurface Utility Engineering (SUE)

“Toolbox” Strategy and the Human ComponentAt the RWF it was decided to adopt a “toolbox” strategy involving the use of multiple tools and technologies. The centerpiece of this ap-proach was a Geographic Information System (GIS). The GIS data-base would be the central repository for all buried utilities. Comple-mentary technologies that are compatible with the GIS were adopted and included: Ground Penetrating Radar (GPR), Mapping Grade GPS (with an accuracy of less than four inches), Electromagnetic Loca-tor, Magnetic Locator, and a Laser Rangefinder. Two dedicated staff members were assigned to oversee this program on a permanent basis. Competence in using GIS, GPS, GPR, and other utility locating tech-nologies and practices were essential skills in addition to construction

management knowledge and having a clear understanding of how the facility is operated.

Key to Success: Subsurface Utility Engineering (SUE)The inclusion of SUE, and linking it to GIS, was critical to a success-ful outcome. The creation of the GIS was a phased approach. First was the development of a Plant Base Map. This Base Map included a geo-referenced aerial photo (flown specifically for the project), upon which buildings, structures, tanks, basins, and ponds were added as polygons. Second, using the Base Map as a reference, the buried utilities infor-mation from the as-built drawings was entered into the GIS. Third, one-by-one, the location of each buried utility was field verified and the data entered into the GIS. Fourth, as-built drawing discrepancies found in the field were corrected. The accuracy of each buried utility was quantified by following the ASCE 38-02 Standard Guideline for the

Behind the Fence: Building a Subsurface Utilities Damage Prevention Program for an Industrial Plant / B Y T I M H A Y E S (GIS MANAGER) & K E N T B R O W N (GIS SPECIALIST) SAN JOSE/SANTA CLAR A REGIONAL WASTEWATER FACILITY

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UsingGIS,theRWFcannoweasilyidentifyexposedburiedutilities.

FALL 2013 I d p - p r o . c o m 35

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Collecting and Depiction of Existing Subsurface Utility Data. Specifi-cally, each buried utility was assigned an ASCE 38-02 Quality Level (QL) A thru D. QL-D represents the lowest level of accuracy; QL-A represents the highest level of accuracy. The engineering design-build process was modified to include SUE. From 10% - 90% Project Design, a subsurface utilities conflict analysis was done. Since such analysis is an iterative process, it was repeated until the project reached 90% design. The locations of buried utilities, and any that could conflict with the project, were identified. Prior to construction, all buried utilities were located and marked. Furthermore, as buried utilities were exposed during excavation they were identified, their locations were marked with GPS, a photo was taken and their depth measured. This data was then incorporated into the GIS for future use.

Return on InvestmentBefore this program was implemented:• Maintenance crews did not know what was buried where before digging.• The costs associated with the discovery of and/or damage to “undocumented” buried utilities during construction ranged from $10,000 up to $1 million depending on project size. • Maintenance crews were spending up to several hours per day manually researching as-built drawings, which resulted in significant construction delays ranging from a few hours to a few days.• Using the ASCE 38-02 Guidelines, 90% of the buried utilities were at QL - D and the remaining 10% ranged from Quality Levels A to C.

After this program was implemented:• All buried utilities are now marked and identified before excavation. Any conflicts are identified and addressed during the project’s design phase. • Costs associated with the discovery of, and/or damage to, buried utilities during construction have been reduced by a significant level.• Staff now has “fingertip” access to a GIS Map Viewer

showing the exact location of buried utilities. This has allowed them to spend, in many cases, only a few minutes in identifying buried utilities in the area where an excavation is to occur. • Using the ACSE 38-02 Guidelines, the following quality improvements were made with reference to buried utilities: 20% are at QL-A, 40% are at QL-B, 30% are at QL-C, and 10% are at QL-D. • Significant improvements to safety and morale have been realized. • Significant reductions in project delays due to the encountering of “undocumented” buried utilities have been realized.

Tim Hayes has an M.S. in Geography with a Certificate in GIS. He has 20 years

of experience in the geospatial technology industry. His focus is on the ap-

plication of this technology to Asset Management, Facilities Management,

Subsurface Utilities Engineering, Pipeline Integrity Management, System

Risk Assessment, Cost-Benefit Analysis, Modeling, and Systems Integration.

Tim can be reached at timothy.hayes@sanjoseca.gov. Kent Brown has a B.A.

in Geography with a Certificate in GIS. For the past seven years, he has spe-

cialized in the application of GIS to subsurface utilities management.

TheCartandTrailerusedtohaulburiedutilitylocatingequipmentaroundthefacility.TheequipmentshownincludesGPS,GPR,EMLocator,amongotheritems.

SUEProcessFlowIterationattheSanJose/SantaClaraRegionalWastewaterFacility.

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