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| Installation of high temperature resistant geomembranes (PE-HTR) in 2012 |
Introduction
Lake Taupo with a length of 40 km and a depth of 400 m is located in the middle of the northern island of New Zealand. Near the lake there are wells, which bring hot water (up to 130 °C) to the surface from a depth of 1500-3000 m. This water is pumped to a nearby power station and used to generate electricity.
Regularly there is excessive water, and with a temperature of up to 100 °C it flows into the artificial lagoons. Due to the high temperature, it cannot be released into a river or a lake because all animal being would die. Thus, it is kept in the lagoons until it cools down to ambient temperature.
Multi layer sealing system
 Hot water lagoon after more than 7 years still successfully in use |
Normal HD-PE is not suitable for this application due to the high temperature of the water. Consequently, a high temperature resistant PE (PE-HTR) was selected for this demanding application and installed in 2012 by AGRU New Zealand. A multi-layer sealing system is used:
- PE-HTR geomembranes (1.5 mm)
- Swell-able geotextile
- HD-PE geomembranes (1.5 mm)
- Geotextile (protection)
- Earthwork
A success story
Several hot water basins were lined using AGRU PE-HTR geomembranes. End of 2019, Mr. Christian Kahr (Head of Business Unit Lining, AGRU) visited the project. “After more than 7 years in service, the PE-HTR geomembranes are still in a good shape and working as designed,” he reports.
