Geomembrane Leak Detection Surveys

Survey Requirements 

For a survey to run effectively it is important the following measures are undertaken prior to Geotect arriving on site:

• To ensure maximum survey sensitivity the cover material above the geomembrane must be completely isolated from the surrounding ground. We generally require a 1 metre wide strip of geomembrane to be exposed around the perimeter of the survey area. This can be achieved by leaving the anchor trenches open. If this is not practicable then clean geotextile protection shall be exposed around the perimeter of the survey area.

• The sensitivity of the survey decreases with increasing thickness of cover material. For best results we would recommend performing the survey after placement of a maximum of 300mm of cover material.

• The sensitivity of the survey is also strongly dependant on the conductivity of the material above and below the geomembrane. It might be necessary to add moisture to the cover material to improve its conductivity, particularly in dry conditions.

• To aid data collection any excessive standing water must be removed from the survey area by pumping.

We are unable to detect holes that do not conduct electricity, i.e. holes with insufficient moisture content or holes that are not in direct contact with the underlying or overlying materials.

If a survey is required directly on protection geotextile, such as side slopes, the geotextile must be saturated throughout. It may also require wetting with a saline solution to aid conductivity.