AS RESIDENTS in the Maclean Lookout area endure day 14 of a "boil water alert" from Clarence Valley Council today, the source of contamination of the Lookout Reservoir remains a mystery.
About 300 properties in approximately the top third of Maclean Hill have been affected by the bacterial contamination and some residents have complained about being "forgotten" by the council.
"If this was happening at the top of Yamba Hill you can bet it would be fixed by now," said one affected resident who asked not to be named.
But the council's manager water cycle Greg Mashiah said this was far from the truth and that council crews, State Government officers and private contractors had been hard at work on the issue since the contamination was discovered and residents notified on December 21.
"Council responds exactly the same no matter which area," Mr Mashiah said.
He said the bacterial levels, although initially higher than the Australian Drinking Water Guidelines, dropped to an acceptable level in the days that followed the alert.
He said the boil recommendation remained in place as a precaution because the source of the contamination had not been found.
Mr Mashiah admitted the timing of the contamination had contributed to a significant delay, possibly up to week, and he had apologised to residents for this.
Asked why no media release was issued about the "boil water alert", Mr Mashiah said the intention was to not panic those in Maclean that were not directly affected by the contamination.
He explained the vast majority of Maclean's properties were serviced by two much larger reservoirs in Roderick St with water drawn mostly from the Nymboida River.
Efforts to get to the bottom of the contamination were stepped up yesterday as CVC workers emptied the reservoir, cleared the silt at the bottom, replaced an old rusty ladder and refilled it by pumping water from the Roderick St reservoir.
Residents' water supply was interrupted for parts of yesterday as this happened, though some in the affected area reported having plenty of water.
Mr Mashiah said crews could not find any evidence of animal contamination in the reservoir and, though any holes at the top of the structure were very small, further netting was being installed.
He said a contamination of the majority of Maclean's water four or five years ago was caused by a single possum defecating in the water supply and when the possum was relocated the problem was fixed.
"It just goes to show how sensitive the monitoring is," he said.
As to the mysterious cause of this contamination, Mr Mashiah said authorities may never know, but there was a small chance it could be backflow from a resident's wrongly installed rainwater tank.
"But we don't have the resources to be able to test every address for this," he said.
Though he could not confirm when the boil water alert could be lifted, Mr Mashiah said he hoped it would be early next week when test results were back.
Some residents took to the Clarence Valley Ratepayers, Residents and Business Owners Facebook page to vent their frustrations, one thread receiving 65 comments.