Ponds

HGI has been advancing the field of pond liner leak location in HDPE lined ponds, landfills and heap leaches using electrical methods for over 18 years.  Typically the ASTM standards for leak detection are not always successful especially in complex lined systems.  Through professional judgment HGI will depart from the ASTM guidelines and tailor the survey design to fit the problem; this philosophy has resulted in an essentially 100% success rate that comes with a long list of client references.  HGI’s strong background in more advanced applications of geophysical methods has served as a launching point for our unique position in the leak detection industry.

 

HGI has been performing pond liner leak location in structures lined with HDPE geosynthetics successfully for over 18 years.  Our years of experience surpass any other liner leak location methods on the market today.

 

Every lined system is slightly different than the next presenting complexities related to infrastructure and overall construction of the lined system.  HGI has the breadth of experience and proven track record to find leaks and qualify the size of them relative to others in the same lined system. HGI’s standard practice is to include a follow-up visit to assist the client in locating the anomalies after the survey has been completed, thus giving the client the assurance that we stand behind our services and interpretations.

HGI has worked on lined systems that include the following:

  • Single lined HDPE Ponds (solution filled)

  • Double lined HDPE Ponds (solution filled)

  • Single lined heap leach pads for the copper and gold mining industry that are typically covered with ore material

  • Double lined heap leach pads for the mining industry that are typically covered with ore material

The principle of  Pond Liner Leak Location and Detection is straightforward: (1) an induced electric current is generated, (2) in the presence of leaks the current flows more readily; (3) results are recorded using a variety of different receiver arrays.  In either a single or double lined system the transmitter circuit is established through use of stainless steel electrodes that are placed in different positions relative to the liners.  Recently HGI has created a multi-channel cable system that can accommodate ponds up to 800 feet in width.  This development allows for safer working conditions because personnel never have to enter the pond.  Given the stringent health and safety standards this is an attractive attribute to our clients.  HGI has also created a floating array that uses a sub-centimeter accuracy GPS system that synchronizes with the measured data which is shown in the below figure.

 

HGI leak detection equipment for Pond Liner Leak Location

Illustration of HGI’s cabling and floating array systems.

 

The cabling approach allows HGI to archive and post-process the data and present easy to understand maps that shows the anomalous readings over the leaks.  Other companies will offer techniques that convert the electrical field readings into an audible signal that operators will listen for while working in the pond.  This approach is subjective, relatively unsafe in comparison to using cable, and the deliverable is a plan map with the interpreted leak locations.  HGI’s deliverable, as seen in the below figure,  will actually show the electrical response in a plan map so that clients can visually see for themselves the amplitude of the anomalies related to leaks in the liner.

 

Hydrogeophysics Electric leak Location data for Pond Liner Leak Location

Example dataset showing the electrical responses over two confirmed leaks.

 

In addition, ponds can be filled to maximum capacity prior to surveying.   This allows for a complete survey for leaks along the slope and bottom of the pond all in one setup. This is logistically easier for the plant operations to fill the pond once instead of in a staggered approach that is conventionally required for techniques outlined in the ASTM standards.