After many years of planning and just over 12 months of construction, the new $3m Braidwood water treatment plant is nearing completion. Over the past few weeks, the principal contractor has been putting the finishing touches to the works and has been running the facility ‘off line’ as part of its own testing processes.
Formal testing of the plant in the company of officials from both Palerang Council and the NSW Department of Public Works are programmed to commence on 25 February. “The demonstration process is a three- day event during which all aspects of the plant’s operation are fully tested,” said Council’s Director of Works, Gordon Cunningham. “Assuming a satisfactory result, there is no reason that the plant would not be put into service after this process – possibly as early as Thursday, 28 February,” he added.
The new plant will be capable of producing two mega litres of treated water per day and is based on a dissolved air flotation and filtration process, known as DAFF. Impurities in the raw water are effectively floated off the top of the filtration vessel by fine air bubbles introduced as a stream of water that is saturated with air. Anything left after this process is captured by the more conventional sand filters at the base of the tank.
“It may be some time though before consumers see the benefit of the higher quality water as it makes its way through the network and replaces the older unfiltered supply,” said Mr Cunningham. A more noticeable change however will be the increase in town pressure associated with the reintroduction into service of Council’s two concrete reservoirs. Recently lined and roofed as part of the scheme upgrade, the reservoirs are expected to add up to an extra 100kPa (about 10 metres of extra pressure) to existing supply pressures. Consumers are encouraged to call 1300 735 025 if they have any concerns.
Other interesting aspects of the plant include an activated carbon and fluoridation components. Activated carbon is an ancillary process that specifically targets issues like taste, odour and, more importantly, toxins that might periodically occur as a result of algal blooms. “It is not expected to be used all the time but is available if we need to address these issues; issues that are more common in river or surface supplies,” said Mr Cunningham.
The fluoridation system will not be commissioned with the plant following this week’s demonstration process since it is subject to its own assessment phase by the NSW Office of Water and the Department of Health. This assessment is likely to occur within the next two weeks after which time routine dosing can occur. “It is a condition of approval for fluoridation systems that formal advice is given to consumers prior to the commencement of dosing and I expect this to occur like it did for Bungendore and Captains Flat through a combination of advertisements and individual letter drops,” said Mr Cunningham.
A public open day will be planned for the plant once all components are commissioned.