Tanks

Subsurface Leak Detection and Monitoring (LDM) using High Resolution Resistivity (HRR) is used in the management of earth material processing, waste storage, and the detection of leaks in containment structures such as landfills, mine tailings, industrial mining and agricultural ponds, and liquid waste tanks. Time based monitoring for changes in the electrical resistivity of the subsurface lithology that surrounds these structures can yield significant information relating to remediation, environmental regulation, and economic impact.

When deployed as a subsurface monitoring system, LDM for subsurface tanks provides stakeholders, managers, and operators with information on subsurface hydrogeological conditions

24 hours a day 365 days a year.

For example, characterization and monitoring of a landfill operation and or other types of waste containment structures informs stakeholders of potential leaks or current plumes beneath those structures. With this knowledge, remedial action can be taken to minimize potential environmental damage and maximize compliance with environmental laws and regulations.

Similarly, information about the subsurface variations in resistivity during a remediation program can be used to adjust procedures and processes in order to improve efficiency, stay in compliance, and reduce costs. Remediation of releases from containment structures can be avoided altogether through subsurface monitoring to detect a leak or breach before it requires an expensive cleanup.

When deployed as a subsurface monitoring system, HRR LDM provides stakeholders, managers, and operators with information on subsurface hydrogeological conditions in near real-time 24 hours a day 365 days a year. This information is readily integrated with the data acquired using a network of electrodes and or monitoring wells. The net result is an enhanced real-time knowledge base to help make better decisions for:

Contaminant Source Identification

Locate Subsurface Fluid Flow Pathways

Characterize Subsurface Plumes

Real-time Corrective Action Monitoring

hydroGEOPHYSICS, Inc. (HGI) currently operates monitoring systems on underground storage tanks at the Hanford facility in Richland, Washington USA. HRR is similar to conventional galvanic resistivity methods but has improved lateral and vertical resolution as well as sensitivity.

The figures below show a schematic diagram of HGI’s monitoring system currently deployed at the Hanford facility, photos of the system being deployed and monitored in office, and lastly a screen capture of HGI’s LDM Online Reporting System. In a blind test on a mock tank, the system detected every release from the tank. In contrast, nuclear borehole logging – which was considered the best available technology at the time – detected zero releases. In addition, the scientists at HGI were able to estimate the volume of the material released to within 14% of the actual volume released.