Colliers Engineering & Design conducted geophysical surveying at a green stormwater infiltration area (rain garden) in the northeast region of Philadelphia, where an open void thought to be a sinkhole was encountered. Using a combination of two- and three-dimensional noninvasive techniques, our professionals delineated the extent and depth of the void and depression. Findings indicated the sinkholes were a result of poor compaction and surface erosion.

The non-invasive geophysical services performed for the client ultimately allowed for an efficient, no-excavation exploration technique for examining and prescribing appropriate remediation methods. Additionally, these geophysical methods allowed for the parking area to remain open and allowed daily activities to continue while the evaluation was conducted.