Fraser Coast Regional Council (FCRC), through Wide Bay Water (WBW), a commercialized business unit of the Council, maintains numerous water supply schemes throughout the region, including remote reservoirs. Reservoirs offer security of potable water supply to the community despite seasonal demands. Additional chlorination may be required to ensure the Australian Drinking Water Guidelines are met.
Reservoirs experience varying seasonal demands which impacts the top-up chlorination required to maintain the chlorine residual levels per recommendations in the Australian Drinking Water Guidelines. While chlorine gas continues to be successfully used, these sites also process low flows of potable water which only require small amounts of chemicals. The selected disinfection technology was to be used at four different potable water reservoirs across the FCRC network. The key parameters to consider and meet were:
• Technology suitable for remoteness of all four reservoir locations
• Minimal operator intervention required
• Minimize residual safety risks associated with chemical handling
• Remove the risk of chlorine gas leaks affecting adjacent community dwellings;
• Attractive return on investment
FCRC also wanted to ensure the disinfection technology could meet the wide operating ranges for these applications. Since the OSEC® system operates as a batching system, disinfectant can be generated to meet different demand cycles for these small flows of potable water.
The OSEC® On-site Electro Chlorination system was selected as it readily produces the disinfectant solution, sodium hypochlorite on-site and on-demand using simply salt and potable water. Generating hypochlorite on demand eliminates concerns associated with transportation and storage of liquefied chlorine gas or commercial sodium hypochlorite solutions. Salt bags can be easily delivered and stored on site with no handling of hazardous chemicals. Combined with the Wallace & Tiernan® MFC Analyser for reservoir water quality monitoring and control, FCRC were offered a safe, simple and reliable system fit for their remote application. The OSEC L system packages were installed and pre-tested in transportable buildings for all four sites, minimizing on-site installation time. This afforded the FCRC team an opportunity to become familiar with the system prior to installation on-site.