Multi-Story Complex Development

Ninyo & Moore performed geophysical locating of existing onsite buried utility lines, buried former basements backfilled with undocumented fill materials including demolition debris, and evaluated for the presence of buried underground storage tanks (USTs). The purpose of our geophysical survey was to evaluate approximate locations of detectable underground utilities and USTs. The findings of our geophysical study were intended to supplement feasibility studies for construction of a large, multi-story complex on the 3-acre site. The site also has areas of ground surface subsidence, parking surface deformation, and void development that could be associated with buried former building foundations and basements that may be backfilled with demolition debris and undocumented fill materials. Ninyo & Moore's services included review of background information, including site aerial photographs, and historical records and data; performance of geophysical surveys at the site including the use of a Geophysical Survey Systems Incorporated (GSSI) SIR-3000 Ground penetrating Radar (GPR) unit, a Geonics model EM61 time domain metal locator, a Schonstedt model GA-52C magnetic gradiometer, a Fisher M-Scope TW-6 pipe and cable locator, and a Metrotech 9860 XT utility line locator; site reconnaissance including field mapping of surface structures at and near the survey areas, and layout of a survey grid referenced to nearby structures; field marking of geophysical anomalies on the ground surface using marking paint, and mapping of these locations based on the survey grid during our field survey; analysis of the data collected; and preparation of a written report presenting our findings, conclusions, and recommendations. The report included the general location and approximate sizes of the anomalies noted, with reference to the field markings placed during the survey. Our survey was conducted during night time hours so as to avoid conflicts with the property's use as a public parking lot during daylight hours.