J R Associates

J R Associates

Utility Locating for Surveyors       Geophysics for Geologists


Providing Utility Locating and Geophysical Surveys Throughout California





PG&E Substation
Utility Locating at a PG&E Substation, San Mateo, CA

For Land Surveyors

We provide accurate utility locations for your existing topo survey drawings. We perform geophysical utility locating to upgrade existing drawings from SUE Levels C & D to SUE Level B.



Learn More

For over 30 years we have been providing surveyors, engineers, and geologists with timely, valuable, and cost effective subsurface information. Our services include:

Time Domain EM Survey in Blythe
Time Domain EM Groundwater Investigation, Colorado River Basin, Blythe, CA
For Geologists

We provide near surface geophysical surveys for groundwater, fault, landslide, and Phase II environmental studies. We offer a variety of geophysical methods and have the experience to apply them.



Learn More




Typical Projects

Below are a few examples of our typical projects.
Utiliy Investigation Along Van Ness Ave

Van Ness Avenue Improvement Project
We performed a utility investigation along Van Ness Avenue to find, mark, and map the unknown mostly abandoned buried pipes that were not marked with the standard USA call.

Santana Row

Santana Row
Prior to new construction at Santana Row, we conducted a magnetic geophysical study to locate, mark, and map buried infrastructure left from the demolition of a shopping center that once occupied the site.


Westmont High School

Utility Investigation at Westmont High School
This was one of the many middle and high schools where we perform utility investigations for local surveyors to add accurate underground utility locations to surface survey maps.

Seismic Refraction  Study, Communication Hill

Communication Hill Residential Development
Near surface hard bedrock was a potential problem for grading at a residential project on Communication Hill in San Jose. We conducted a seismic refraction survey on the hill to map the depth and strength of the underlying bedrock.



J R Associates Civil and Environmental Geophysics

Morgan Hill · California · 408-293-7390

jra@greatgeophysics.com