GIS PROJECTS
DAY CARE FACILITY UTILITY LOCATE
Plateau Geoscience Group conducted a Ground-Penetrating Radar (GPR) survey to determine whether a sewer line was present in an area proposed for construction at a day care facility in Portland, Oregon. The GPR survey was made in the facility’s entrance area and in the central portion of the parking lot. The raw data was collected onsite then processed using GPR Slice v7.0 software. A sewer line was not identified in the entrance area, and a shallow trench ending at a subcrop of basalt was identified in the central portion of the parking lot.
GEOPHYSICAL SURVEY STATE HIGHWAY 20, ALBANY OREGON
Oregon Department of Transportation will be upgrading portions of State Highway 20 between Albany and Corvallis, Oregon, to improve the roadway with wider lanes, bike facilities, signs and road markings. Plateau Geoscience Group, subcontracted to Foundation Engineering Incorporated, conducted a Ground-Penetrating Radar (GPR) survey of the first three segments of the upgrade project. The purpose of the survey was to identify the longitudinal edge of the original Portland Cement Concrete (PCC) lanes that were constructed in 1925. GPR profiles were measured perpendicular to the road lanes and the data processed using GPR-Slice 3D software. The processed data revealed the original PCC slab as well as other features including localized subbase deformation, historic buried Willamette River side-channels, and post-1925 highway construction additions. GPR processed data will be used to aid in locating geotechnical boring locations and during highway construction to protect the underlying PCC slab.
THRIFTY AUTO LONGVIEW
A geophysical survey was conducted at the Thrifty Automart site located in Longview, Washington, to identify potential environmental issues related to historic use of the site to be addressed prior to a future property sale. One historic use of the site was as a gasoline station. An initial detailed electromagnetic (EM) investigation was performed across the site using a Geonics EM-61 MK2 to identify potential metal objects in the subsurface. The data was modeled using Surfer 9 to produce a site map showing identified anomalies. A ground-penetrating radar (GPR) investigation using a Mala Easy Locator (350MHz antenna) was made of each anomaly identified by the EM method. Subsurface object dimensions were marked on the pavement and geolocated using a handheld Trimble GHX global positioning system system (GPS) unit. Three underground storage tanks were identified, along with storm water lines and product lines in a back-filled trench.