Water Puddle Method

The water puddle method allows technicians to identify and locate potential leaks, faults or tears in a geomembrane occurring during installation. It applies a geoelectrical technique that harnesses the electrical insulation properties of geomembrane materials.
A DC voltage is applied to metal roller that sprays water across the geomembrane surface and a grounding electrode is placed in the earth outside of the test site, creating a difference in electrical potential between the roller and the underside of the membrane.

If the roller passes over any faults sufficiently large for the water to leak through the circuit between the roller and the grounding electrode is completed, and a technician is notified by their detection equipment.

As it only requires a thin layer of water to be applied gradually to the geomembrane, the water puddle method allows for technicians to perform tests with 100% coverage even on extreme slopes and uneven surfaces, with a resolution capable of identifying leaks and faults smaller than 1mm2. Groupe Alphard applies the method as standardised by ASTM standard D7002.