Engineering - Surveying - Material Testing 

Civil/Environmental Engineering Consultant of Choice

2679 Continental Drive
Green Bay, WI 54311

Phone: (920) 465-3911
Fax: (920) 465-3913
Email: ambrosius@cqminc.com




 •Civil/Environmental Engineering
 •Property and Construction Surveying
 •Engineering Graphics
 •Laboratory Material Testing
 •Electrical Leak/Liner Integrity Survey


Electrical Leak/Liner Integrity Survey

CQM, INC. provides professional services for performing Electrical Leak/Liner Integrity Surveys for installed geomembranes.  Electrical Leak/Liner Integrity Surveys consist of a nondestructive method to locate defects (leaks) in geosynthetic liners following all installation activities.  The final step in a complete Construction Quality Assurance (CQA) program, many regulatory agencies and facility owners are requiring (or at least encouraging) a liner integrity survey following all construction activities.

 Find Leaks In:
  • Liners
  • Sumps
  • Ponds
  • Pools
  • Basins
  • Lagoons
  • Tank Liners
  • Secondary Containments 
Despite being covered with a nonwoven geotextile, a 1 1/2-inch diameter stone punctured the 60-mil geomembrane.

Even the best construction supervison and CQA efforts during geosynthetic installation can be compromised with the improper placement of protective cover soils.  In fact, nearly 75% of liner damage occurs during the placement of the overlying protective or drainage layer material. 
   Small cut in the geomembrane
- occurred during installation.
The post-construction leak location survey method involves placing one electrode within the protective cover soil above the geomembrane.  A second electrode is placed within the conductive material under the geomembrane.  For a single geomembrane liner system, the subgrade soil acts as the conductive material.  In the case of a double-liner system, the electrode is placed between the upper and lower geomembranes.
Damage to geomembrane from a dozer placing
the 1-foot sand layer.


A high voltage electrical current is then applied to both electrodes.  Because the geomembrane liner acts as an electrical insulator, current will only flow through leaks.  As current flows through a leak, it produces a localized area of high current density.  A trained engineer or technician traverses the surface of the protective soil cover with a data recorder, recording the electrical potential values.  When an anomalous area (i.e. high current density) is identified, the cover soil is removed and the geomembrane is examined for defects or damage. 
 Diagram of the electrical leak location method for surveys with soil covering the geomembrane

Whether your project requires a complete CQA inspection program or simply a leak location survey, CQM, INC.’s staff of experienced engineers and technicians are capable of meeting your needs.

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