Applications — Русский

Roof Leak Detection

SOLUTION FOR FLAT ROOFS – SENSOR DDS® TECHNOLOGY

The most used and effective way of testing the liner integrity on green roofs is to survey using SENSOR DDS® technology. As the technology is based on the distribution of the geoelectrical field below and above the liner the problem could be presence of the thermo-isolation which is non-conductive.

Sensor leak detection geotextile is installed as a standard geotextile with an overlap of minimum 100mm. After installation of the geomembrane we can test its integrity using the SENSOR DDS® MIT portable Arc Testing device. In this step we can eliminate every pinhole found in flat areas or corners.

For the next step a drainage gravel layer is carefully installed on top of the tested roof liner.  The final test of geomembrane integrity is completed using our SENSOR DDS® Mobile dipole testing kit which identifies tiny damage caused by sharp stones when placing the overliner.

Tailing dam leak detection

Exposed and covered liner integrity testing at Tailing Dam – Gold mining

A tailings dam is typically an earth-fill embankment dam used to store byproducts of mining operations after separating the ore from the gangue. Stored tailings can be liquid, solid or slurry of fine particles and are usually highly toxic. Therefore a protection of the environment surrounding the tailing dam should be the highest priority. To stop the leakage of toxic material from the tailing dam to its sub-grade and contamination of groundwater SENSOR DDS® technology should be used. To test the integrity of the sealing layer of a tailing dam after its installation in order to detect and locate the leaks we use the Arc Tester – SENSOR DDS® MIT. For testing the geomembrane integrity after placing an overliner (gravel) we use Sensor’s dipole testing kit SENSOR DDS® Mobile.

Arc Tester – SENSOR DDS® MIT and SENSOR DDS® Mobile dipole survey

General project info:

• Area tested was 283 000m²
• Single layer of HDPE 1.5mm geomembrane installed
• Protective layer: 500mm gravel
• For exposed liner testing Arc Tester SENSOR DDS® MIT was used
• For covered liner testing SENSOR DDS® Mobile was used

During the testing of bare geomembrane integrity at the Tailing dam at a gold mine’s project we detected and located 132 holes in total. Most of them represented cuts or weak extrusion welding. However holes caused by cigarette burns were also a very common damage. The average productivity at this project was 9 500 m² per day per operator. We have visited the site multiple times following the progress of geomembrane installation.

The installation of the overliner (drainage protective layer of gravel) took place after the whole area of geomembrane was tested using Sensor DDS® technology. The total damage found during our testing was 102. The most common damage (more then 50%) was so called puncture from above caused by gravel penetrating through the liner from above. This happens when heavy machinery places the protective overliner in position onto the geomembrane and the force from when it turns sharply also creates large tears or cracks in the geomembrane.

We have helped the client prevent a lot of issues and save money by identifying these future leaks at the time of installation. It would be very expensive and technically difficult to repair these leaks when the Tailing Dam would be in full operation.

Landfill leak detection

Municipal solid waste landfill

This is a site for domestic day-to-day waste disposal. Its also known as tip, rubbish dump, dumping ground, etc.

The material stored at a solid waste landfill is isolated from the environment by a sealing layer which can be HDPE or LDPE or even PVC geomembrane. If such geomembrane leaks, the contaminant from the landfill spreads in the direction of the groundwater flow. This way it can travel long distances and contaminate the environment for a long time. Such contamination can cause health problems and not just to the people living near the vicinity of the landfill.

In such cases we use the SENSOR DDS® Mobile – dipole survey after installation of the drainage/protective layer to locate any damage which could occur while placing the overliner onto the geomembrane. For example at a landfill in Asia where after the installation of the protective drainage layer we located 15 faults on the geomembrane using our portable testing device for covered geomembrane – SENSOR DDS® Mobile.