Flooding in the Goulburn River recently saw different organisations and businesses adjust their operations to work around the gradual spread of water up the banks.
However, one organisation, Goulburn Valley Water, dealt with a different side-effect of the flooding: high levels of raw water contamination from the Goulburn.
This saw treatment processes being shut down for the organisation for six hours on the evening of Sunday, January 14, to Monday morning, resulting in water conservation rules across Greater Shepparton for two days.
Here’s everything that happened in those 48 hours, according to GV Water’s incident controller, Steve Nash.
Due to the constant changes of the water quality in the river, which is common during flood events, GV Water needed to make adjustments in line with those changes to ensure treatment processes remained stable, Mr Nash said.
“On Sunday, the water quality changed quickly, which put this out of balance, particularly after running treatment processes at high rates over a long period of time,” he said.
“This forced us to suddenly and unexpectedly shut down the plant, where we had to fully flush two of our three separate water treatment processes before we could reset.”
This led to GV Water being unable to treat water for around six hours between 8.30pm Sunday and 1am Monday.
Mr Nash said as a result, they started implementing backup processes to restore water storage levels to normal.
This was then shared with Greater Shepparton residents via text message that night.
“To ensure we could continue to meet demand, we drew down our treated water storage reserves, so we asked customers to reduce their non-essential water use to take the pressure off the plant while we worked to restore full treatment capacity,” Mr Nash said.
“Specialists were working around the clock and managed to get processes running again at about 1am on Monday morning at about 30 per cent of normal capacity.”
However, the ‘conserve water’ request still needed to stay in place for Greater Shepparton residents as the water at that stage would only be able to meet half of the daily demand.
On Monday, the Goulburn’s raw water quality started improving, and throughout the day, capacity was slowly increased to 50 megalitres per day, which was the maximum it had been running at due to poor raw water quality because of the floods.
By Monday afternoon, the plant could be brought back to its full treatment capacity rate of 70ML/day and the depleted water storages started getting refilled again.
Across Monday night and Tuesday the treated water storages in Shepparton continued to refill and by Tuesday night, it reached full capacity and the water conservation period was able to come to an end, Mr Nash said.
“We’d like to thank everyone for their help in reducing their water usage over the 48 hours, including industrial customers who also helped to reduce their demand,” Mr Nash said.
“We’ll continue to closely monitor the plant over the next couple of days and we will have staff on-site to continue regularly testing the raw water and adapting the treatment process as necessary.”
Mr Nash said even though raw water quality was improving, there are still some differences customers might be noticing.
“We are still seeing really high levels of discolouration (about 10 times higher than normal) in the supply from the Goulburn River, so it means we need to adapt the treatment process,” he said.
“Some customers may be noticing a change in the taste of their water as a result – this is only temporary and will return to normal as the raw water quality continues to improve.
“We are already seeing improvements in the raw water quality, with the colour dropping from a level of 300 over the past couple of days to 200 (on Wednesday, January 17), and we’re expecting this to continue to improve over the next couple of days.”
Mr Nash assured customers that the water was fully treated and safe to drink and was maintained that way during the 48-hour period.