Various durations have been suggested at various times, and I...

Various durations have been suggested at various times, and I even heard 9 months mentioned in a conference call.

The ponds were designed for 13oo mm evaporation per year following scale up from the pilot pond results of 1733 mm/year and with allowance for brine activity etc (its all in the NI43-101..). On that basis the design annual evaporation on a 4.5 km2 pond system is therefore around 5.8m m3 of water. They have reported pumping around 180 l/s of brine which runs to.... 5.7m m3/year. It is not evaporated to dryness of course - roughly a ten-fold concentration... but, in any case, you can see the system seems to be designed to something a little under 12 months in "normal" year.

In reality, they also hold inventory in the system. At various times, they have reported inventories of around 38,000 t LCE. This suggests a mean residence time of a little over two years at nameplate.

How quickly can they bring a new pond on? Just as quickly as they can redistribute some of that brine inventory. Ultimately the inventory will rise in line with the increase in pond area, but they can access the increased evaporation area somewhat sooner than the 1 to 2 year discussion would suggest. The three year reference for the harvest ponds is in respect to the clean out cycle for clearing the accumulated sylvite salts.