Technology

HGI has extensive experience providing leak detection and leak location technology on impoundment structures (buried tanks, ponds, pipes, dams, lined storage facilities) for commercial / industrial and nuclear industries (see About HGI for a detailed background). We work successfully on dry or solution filled structures, single or multiple leak locations, and resistive or highly conductive solutions. The cause of a leak is as important as finding the leak location.  Typically leaks are caused by improper design of construction (weak welds or joints), faulty materials (defects), structures operating beyond design constraints, and accidental damage (cuts, tears, bullet holes, etc).  Whether it is a double-lined or single-lined pond, metal or concrete tank, we have the technology to find the leak location and uncover the cause of the leak to help prevent future failures.

HGI has extensive experience providing leak location and leak detection technology…

Our technologies are rooted in electrically-based geophysical methods; electrons will flow where water flows.  Once electrons start moving, an electrical field is established, and HGI can map the field to determine the leak source.  Alternatively, if electrons are not flowing, then your containment system is sound and you can rest assured that a leak has not occurred. We have developed  specialized technologies, innovative methods, and cutting edge instrumentation to support the following areas:

Leak Detection & Compliance Assurance

Surveying of an impoundment structure which is suspected of leaking is completed in order to determine the location of one, or several leaks, so that repairs can be completed.  Most often this can be accomplished in a single survey using portable equipment and methods that are non-intrusive / non-destructive.  Our surveys are also used to verify and validate that the structure is not leaking.  Many of our clients have reduced their operating costs and prevented potentially large failures by contracting HGI to complete quarterly or annual leak detection “snapshots”.  This proactive maintenance allows our clients to recognize problems while they are small enough to repair without lost work and often serves to improve their relations with regulators and environmental auditors.

HGI geoscientist performing leak location survey on a HDPE geosynthetic liner at a Nevada mine

The image above shows an HGI employee conducting a leak location survey of an impoundment structure.

Leak Detection Monitoring

This involves the permanent installation of leak detection instrumentation on the impoundment structure to provide daily, monthly, or quarterly leak detection monitoring.  Monitoring for the potential of a leak reduces environmental risk.  We define risk as a chance of an adverse outcome, identifying both the probability of a leak, and the consequence.  Depending on where your site lands on the risk spectrum, we can develop a coherent plan for monitoring your site.  For example, we provide a permanent, real-time solution to the US Department of Energy (US DOE) for monitoring nuclear waste storage tanks.  At the Hanford Nuclear Reservation, many of the tanks fall under the risk spectrum of moderate to high probability, very high consequence.  Since containment redesign is not an option, the only interim solution is monitoring with a very high frequency of reporting; currently 15 minutes to an hour continuously since 2004, over the last 10 years, 24 hours a day.

HGI personnel posing with the hydrogeophysics Leak Detection & Monitoring system at a tank farm on the Hanford Nuclear Reservation in Washington State.

Our system provides immediate web-based and text messaging feedback if a leak were to occur.  Also, if for any reason the system is adversely affected  by a power failure, a break in a wire, or a suite of other issues that affect the performance,  instantaneous feedback is sent to the operator so  the problem can be addressed.  At other locations we provide less frequent (quarterly and yearly) assurance monitoring to ensure that our client remains in compliance with state regulators.

 Leak Plume Mapping

Leak plume mapping involves completing a characterization survey mapping the location and boundary of a plume associated with a leaking impoundment structure in order to support remediation activities. Historical leaks almost always leave some evidence behind that can be mapped with geophysical methods.  HGI is a full-service geophysical consulting company that has conducted many surveys mapping the extent of plumes as a result of containment failure.

Example plume mapping data from an electrical resistivity survey. The plume is due to loss of containment from a tank. Data were collected along three parallel lines spaced about 100ft apart.