Seawater contains just over 2.5 per cent sodium chloride, together with significant amounts of other salt. Some 60,000 to 70,000 tonnes of salt are harvested from Lake Grassmere each year. Sea water is pumped into the 688 hectare main lake continuously throughout summer.
As nature does its work and evaporation increases the sea water’s strength, it is pumped into a series of concentrating ponds, where further evaporation takes place.
When the brine reaches saturation point it is transferred into …