Reverse osmosis plant producing high quality water
Tuesday, 5th January, 2016
By Andrew Robertson
It’s been mired in controversy but there’s one thing residents can’t complain about when it comes to the city’s new reverse osmosis plant - the quality of the water.
The switch from Copi Hollow to Weir 32 for town supply this week has coincided with a 30 per cent drop in salinity levels, as the local treatment process now incorporates a desalination stage for the first time.
“It’s been reduced from about 1080 EC (electrical conductivity) from Copi Hollow down to 777 EC and even lower this morning,” said John Coffey, Essential Water’s manager of water supply and quality.
“So you’ll notice it’s very good quality water now in Broken Hill due to the RO plant.”
The city’s need for the plant in the first place has been criticised by many residents, who blame the Murray Darling Basin Authority and government for the current water shortage.
The RO plant, which is capable of desalinating up to 10 megalitres of water a day, will allow Essential Water to continue to draw on surface water at the Menindee Lakes until supplies are exhausted.
That will be in about 18 months’ time on latest estimates, according to Essential Water’s operations manager, Guy Chick.
“All the forecasts we have ... surface water at Menindee is going to be good until about mid 2017.
“That’s a fair way off, admittedly it’s going to be getting saline, but that’s if nothing happens.”
Heavy rain fell over parts of Queensland at the weekend, including in the Warrego district, which could result in flows into the parched Darling River.
Even if the Darling does not receive any substantive flows, Mr Chick said he did not expect the city to move beyond Level 3 water restrictions, which serve to limit the city’s total daily water consumption to 13 megalitres.
“If the community works with us we can get by on level three,” said Mr Chick, adding he was aware there would be some “discomfort” with the restrictions.
As Broken Hill moves to Weir 32 for its supply, the Menindee township has switched to bore water.
Mr Chick said the town began to be supplied with water from the bore field, located on Menindee common, instead of Copi Hollow about a week ago.
“We’ve upgraded the filtration plant at Menindee specifically to treat some of the special peculiarities of bore water and that’s what’s happening now.
“There’s been rumours that the bore’s failed; the bore’s working beautifully but we’re still just doing basically commissioning to fine tune the treatment.
“As of about early last week that’s when we started drawing on the bore for the commissioning process.”
He said Menindee was purposely on an earlier switch-over date to Broken Hill because “we wanted to have a bit of a lead period just to make sure the bore was fine and our process was fine”.
“I think we might have reverted back to Copi late last week for a few days. Once we bring water into Broken Hill from Weir 32, Menindee will be on bore.”
Mr Chick said Menindee would only be on bore water until surface water supplies were replenished, which would improve water quality.