Dampier Salt Limited (The Company) is a member of the Rio Tinto Group and is the world’s largest exporter of solar salt. DSL Operations are located in Western Australia at Dampier, Lake Macleod and Port Hedland. The Port Hedland growing process uses brine concentrated from seawater to produce salt in crystalliser ponds. The seawater intakes are located 20km away, and brine travels this distance through a series of pumps and gravity fed ditches to the crystalliser field.

Brine Ditch #3 runs from pickle pond 9 (PP9) to the crystallisers and supplies the field with brine delivered from the intakes. Below ground syphons 109, 110 and 111 allow the gravity fed brine to travel below a series of tidal creeks.

These syphons were designed to carry up to 7700 m3/hr and are between 1.2m and 1.4m in diameter. These Syphons were built in 1967 and have reached end of life and are in need of replacement. Furthermore, gypsum build up on these syphons have decreased their flow capacity, creating a bottleneck for the production process.

The Project Scope of Work for this Project included:

• Removal of existing steel syphon pipe at 3 locations within brine channel No. 3
• Replacement of each syphon with 1600mm dia corrugated HDPE syphon
• Associated earthworks to backfill trench and shape inlet and outlet
• Supply, place and construct reinforced concrete inlet structure including FRP
• Stairway and platform and steel trash rack
• Supply and place 500mm thick facing class rip rap through creek crossing above
• Syphon pipe and at syphon outlet.
• Replacement of a section of HV Cable crossing Syphon 111, and installation and
• Management of temporary generator to supply nearby aboriginal community