17 Nov MIWB implements revised chlorine dosing strategy
Following a successful trial, MIWB has adopted a revised chlorine dosing strategy reducing costs and improving water quality outcomes.
Mount Isa Water Board Chief Executive Stephen Farrelly said for many years Clear Water Lagoon was the focus of water treatment for Mount Isa. “Since the 1980’s water treatment consisted of the natural reed bed process followed by chlorination to provide disinfection. Chlorine was further topped up once the water arrived at the terminal reservoir on the outskirts of Mount Isa. In this way the residual chlorine was maintained to prevent biological regrowth.”
“Water treatment is now focused on the new filtration facilities located close to the city. In this changed setup it makes sense to review the overall approach.” Mr Farrelly said, “By reducing the amount of chlorine added before the treatment plant, we are able to not only reduce the cost to customers, but also reduce the occurrence of unwanted chemical by-products resulting from chlorine reactions. The amounts of these chemicals allowed in drinking water is regulated to ensure there is no ill effects, but now Mount Isa’s water is 40% below the limit set in the Australian Drinking Water Guidelines”.
“Customers are being delivered the same concentration of protective chlorine in the water and this ensures the water continues to be safe” Mr Farrelly said “but now, not only is the water safe, it is also significantly improved in quality”.