Geophysical Utility Investigations

A Perdue University study commissioned by the Federal Highway Administration found a total of $4.62 in savings for every $1.00 spent on utility investigations. J R Associates has been performing utility investigations for over 25 years for major utilities including the East Bay Municipal Utility District, the Santa Clara Valley Water District, the San Francisco Public Utility Commission, and Pacific Gas & Electric. We have performed geophysical utility investigations along proposed pipelines, at water treatment plants, pumping facilities, power plants, pollution control facilities, schools, industrial parks, military bases, refineries, and shopping malls.


The main benefit of a geophysical utility investigation is saving money by finding unidentified utilities before they are hit during construction. Additional benefits of geophysical utility investigations are:

  • Reduction in unforeseen utility conflicts and relocations
  • Reduction in project delays due to utility relocates
  • Reduction in claims and change orders
  • Improved safety for the construction crew
  • Reduction in delays due to utility cuts
  • Reduction in project contingency fees
  • Lower project bids
  • Reduction in costs caused by conflict redesign
  • Reduction in the cost of project design
  • Reduction in travel delays during construction to the motoring public
  • Improved contractor productivity and quality
  • Reduction in utility companies' cost to repair damaged facilities
  • Minimization of utility customers' loss of service
  • Minimization of damage to existing pavements
  • Minimization of traffic disruption, increasing project's public credibility
  • Improved working relationships between project and utilities
  • Increased efficiency of surveying activities by elimination of duplicate surveys
  • Facilitation of electronic mapping accuracy
  • Minimization of the chance of environmental damage
  • Savings in risk management and insurance

Geophysical Utility Investigation Example

A recent investigation performed along a seven mile proposed pipeline through Alameda County is a typical example of a geophysical utility investigation. The project's owner provided us traditional plan and profile drawings for the proposed pipeline. The plan showed existing utilities that were found from extensive research of utility records and pertinent as-built information from utility owners. The plans included surveyed field observations to identify visible above ground utility features such as manholes, valve boxes, and fire hydrants. The plans identified approximately 360 utility crossings and potential conflicts. Our scope of work was to walk the route from beginning to end using utility locators and other geophysical equipment to identify, mark, and map utilities that were not previously discovered. Geophysical utility investigations find between 10% and 50% more utilities than record searches and visual observations alone.

Typical City Street

                                                    Plan view of utilities found during an investigation

Results And Cost Benefits

During the investigation we confirmed the location of over 360 known utilities and found 31 utilities that were not previously identified or located. The utilities found during the investigation were marked on the pavement with paint following the American Public Works Association's color scheme. For the majority of the utilities found during the investigation the location found in the street corresponded to the location shown on the drawing. The 31 previously unidentified utilities were noted and added to the plan and profile drawing. The direct savings to the project was estimated to be over $130,000. The indirect benefits included reduced construction delays due to utility cuts, reduced travel delays to the motoring public, improved safety for the construction crew, and an increase in the project's public credibility. Please contact us to find out more about how our expertise can benefit you.

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J R Associates, 1886 Emory Street, San Jose, CA  95126

Ph: (408) 293-7390,  Email: