I am looking at a repairing a defective evaporation pond liner which is made up of 2 layers of HDPE with a proprietary drainage membrane between them. The top layer is damaged and we have a contractor in place ready to remove and replace this. The scope of works calls for the bottom liner to be visually inspected but I feel defects and damage could be near impossible to spot with the naked eye. A vacuum box test only does where it touches and is usually limited to the welds. I understand that a holiday test won’t work as the bottom liner is on the ground and the test will short out. Is there another test I can do on the entire liner (approximately 35,000 sq m)?
On a slightly different tack, we have found water between the HDPE liners on the outside of the pond berm. The pond is 225m x 150m and the water is usually 1.5 m deep, the berm is 2.5m high. I would have thought that any water between the liners would not have gone much above the pond water level. An office wag has ventured that the water in the pond must have pressurized the water between the liners and forced it over the top of the berm. Is that possible?
On a slightly different tack, we have found water between the HDPE liners on the outside of the pond berm. The pond is 225m x 150m and the water is usually 1.5 m deep, the berm is 2.5m high. I would have thought that any water between the liners would not have gone much above the pond water level. An office wag has ventured that the water in the pond must have pressurized the water between the liners and forced it over the top of the berm. Is that possible?
