Newfoundland and Labrador sailors have been working around icebergs for centuries, but it is until recent years that the quality of iceberg water as a natural source of potable water has turned harvesting into a specialized trade.
Icebergs are calved off the ice-shelf of Greenland into the Labrador currents. They arrive in Newfoundland waters during the spring and early summer, and can be harvested until late September. Icebergs vary in size, shape and location.
According to the harvester, knowing where and which iceberg to harvest and how to remove the ice without having the iceberg roll is a mixture of “experience, sound judgment and safe, practical skill”. The preferred iceberg is grounded, in a sheltered location and has an irregular shape and multiple protrusions.
The ice is harvested using a vessel to approach the iceberg and a smaller boat to collect portions of it. Harvesters look for conveniently sized pieces or wait for them to break off of the iceberg, then scoop them with a large nylon square net. They throw it over the ice assuring the lines tight and tying it along side the speedboat.
On rare occasions, when broken pieces can’t be found, the icebergs are encouraged to founder by the sound of a gun being fired. Other times, portions are obtained by cutting directly into the iceberg with chainsaws and wedges. The resulting size of these portions is between 1 to 5 tons (called growlers).
The main vessel lifts the portions onto the boat deck with a crane. The ice is rinsed with potable water, however, icebergs have the same density as concrete and salt water does not penetrate them. An alternate method of cleaning is to wash the surface with high pressure steam. The ice is then cut into smaller pieces and placed into 150 liter drums. Some of the melted ice is also pumped into 1,000 liter holding containers.
The ice in the drums is permitted to melt naturally using ambient temperature. The quality of the water is tested and confirmed to be suitable for processing. If there are any impurities in the water it gets discarded. Most of the iceberg water that is collected has a low reading and often reads zero parts per million.
In other occasions, depending on the quantity of water required, harvesters tow a one million liter barge supporting a grapple crane that breaks off pieces of ice which are then crushed and melted in storage tanks. The water is then transported to the bottling plan and pumped into receiving tanks. They can harvest about 100 tons of ice a day (1 ton equals approx. 1,000 liters of water).