Some areas around Dubbo had their boil water alert lifted on Wednesday 20 July following the first lifting of the alert on Monday 18 July in some areas but plenty of residents are still forced to boil their water.

Speaking with the Daily Liberal on Friday 22 July, Dubbo Council mayor Mathew Dickerson said some aspects of the way NSW Health determines when a boil water alert is lifted isn't taking 'common sense' into account.

"It's been an interesting process we've had, some common sense has prevailed along the way, but it is still frustrating. Because if it was council's decision to make we'd have lifted the boil water alert across the entire city, it'd be done, finished," Cr Dickerson said.

"But, we've got to work with NSW Health and we're going to take note of what they say. And so they've still got processes in place which may not be entirely logical, and they're introducing new methodologies for this boil water alert for us, which doesn't seem like it's quite sensible.

"I make no excuses... it's our water treatment facility and we were below the spec that we're meant to be."

Councillor Dickerson explained that prior to November 2020 the threshold level of water turbidity was one per cent, currently that threshold is 0.5 per cent.

"If we go back before November 2020, we wouldn't have had a boil water alert, we wouldn't have had to notify NSW Health. Staff would have been working away in the water treatment plant and thought 'oh gee, the turbidity is getting a bit higher, we're gonna keep that down a bit low', and everything would have been fine," he said.

He explained that on 7 July the water treatment plant produced water above the 0.5 per cent threshold for 10 hours and 18 minutes. He continued to explain that while council has flushed the water system twice, NSW Health imposed a 0.1 per cent threshold for the old and new water coming in which could have forced the alert to be in place for more than a month. Cr Dickerson said council brought in external consultants to argue the point with NSW Health around the strict guidelines and came to an agreement that a more reasonable one per cent level can be attained. In addition, he said that NSW Health did not accept the testing council had done for traces of cryptosporidium in the water.

"It's a bit frustrating from our perspective. What we're working with at the moment is what we've been given, which is the one per cent target. We're slowly going through and working through the reservoirs until we can demonstrate to NSW Health that each reservoir is down to that 1 per cent dilution level, by the flushing that we're doing and bringing new water in, etc," Cr Dickerson said.

NSW Health in its defence said safety was their 'highest priority'.

"The Western NSW Local Heath District (WNSWLHD) Public Health Unit (PHU) recommends a boil water alert be put in place when there is an ongoing health risk in the water supply that can be managed by boiling," a WNSWLHD spokesperson said.

"Boil water alerts are established to ensure the safety of communities and help reduce the risk of avoidable illness due to water contamination, which can occur for a number reasons, including heavy rainfall or flooding.

"Sometimes boil water alerts can be resolved quite quickly, however in large towns with complex water supply networks, clearing contamination from the network takes longer than it typically would for smaller networks.

"We understand that the boil water alert causes inconvenience. Dubbo's will be lifted when safe water is available to the whole community.

"The PHU is continuing to work with Dubbo Regional Council (DRC) to confirm that Council has flushed safe water through the network and can progressively assure the safety of the drinking water.

"DRC has done a fantastic job so far ensuring community health is not adversely impacted by recent water contamination using a staggered approach to flushing and diluting reservoirs."

Councillor Dickerson said he shares the frustrations of residents and that council will investigate how to avoid such restrictions in the future.

"Once we're out of this we need to do a full analysis, see what happened, see how we can prevent it from happening again. It was a fairly unusual circumstance, the turbidity in the river to be so high," Cr Dickerson said.

"We need to make sure that we can handle a highly turbid river again, we will get more of these things in the future as climate change has more of an impact. We're going to see more extremes back and forth."

Councillor Dickerson said one way council could potentially prevent the issue in the future is through their bore network.

"One of the solutions without a doubt will be to take more water from our bores in future if the river becomes more turbid. We were doing that anyway.... from a drought perspective, not from a flood perspective. But as it turns out, that might be a good solution for that as well. That's me speaking, without really doing a full analysis...," he said.

"I just think the thing that I would say is thank you to the community, the community has been very understanding about it. And the community has done the right thing, they've all boiled their water, they've been very safe and we haven't seen any outbreak of crypto [cryptosporidium], we haven't seen any major illnesses in the community.

"We'll keep doing this [lifting the alert] one or two reservoirs at a time. It will probably take us another 10 days before we get all the rest of the reservoirs based on these low dilution levels that the government wants."