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.