High Temperature Resistant (HTR) geomembranes

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

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 pools were sealed with AGRU's PE-HTR geomembrane. Even about a decade after their installation, AGRU's high-temperature resistant geomembranes are in pristine condition.