Challenge Broken Hill has relied on the Menindee Lakes as the town’s main water supply since the 1960’s. The Menindee Lakes is a chain of shallow ephemeral freshwater lakes connected to the Darling River to form a storage system. In late 2015, due to the drought conditions in the Darling system the capacity of the lake system was close to empty. This not only limits supply of water but also impact on the quality of water which deteriorates (salinity increases) due to the high evaporation rate. Under these conditions, Broken Hill’s Water Treatment Plant, designed to remove turbidity and organic matter using conventional filtration process, requires an upgrade with the reverse osmosis process to remove the excess salinity.

Therefore the requirement for an RO plant arose, which required completion in a very short time frame - 12 weeks, very careful installation and integration with the continuously operating upstream water filtration plant, along with numerous procedures and measures to comply with from the NSW Public Works who managed the overall project on behalf of Essential Water, the owner and operator of the Broken Hill WTP.

The new RO plant was required to be integrated with the existing water treatment facility on site - successful integration would require close management of the equipment interfaces.

Solution With a 12 week time frame, the project was completed in a very short time frame to all required standards set out by the NSW Public Works.

Osmoflo installed a 6MLD BWRO plant on site in 2005, however this needed to be upgraded with another 4.5MLD capacity in order to meet the potable water production requirements as well as minimise the saline waste produced in the process. 

In the 12 week timeframe provided, Osmoflo:

• Recommissioned the 6MLD BWRO previously installed but not used since 2006 and to make up the 4.5MLD to increase the capacity to 10.5MLD, by installing 1 x 2.75MLD BWRO and 2 x 1MLD SWRO – on a rental basis.
• Fabricated and installed a new common RO plant feed & blending pumping systems
• Fabricated and installed a new common CIP system
• Fabricated and installed a new electrical distribution system for the rental equipment
• Installed new tanks as required
• Integrated the entire 10.5MLD RO plant on site with the existing treatment facility (via the client’s existing SCADA system) and integration of the raw water pumping station that supplies untreated natural source water to the WTP site

The disposal of brine was limited to a volume of 2ML/d, requiring the RO plant to achieve up to 90% recovery to remain within the daily limit. Given the water source is challenging at these levels of concentration, Osmoflo drew on some of its experience from developing its patented Osmoflo Brine Squeezer technology in-house to achieve the high recovery.

Result Osmoflo delivered the full 10.5MLD plant, meeting the client’s needs in all aspects of the project. By delivering the project at this time, Osmoflo helped ensure the short term quality potable water supply for the town and provided the time required to develop long term solutions for Broken Hill’s water supply.

Essential Water is part of Essential Energy's Network Operations division and provides water supply services to over 10,000 customers in Broken Hill, Menindee, Sunset Strip and Silverton. In addition sewerage services are provided to Broken Hill