The positive test for E. coli came last week, in a water quality sample taken at Karitane on Thursday.
But daily sampling of the network supplying all three communities has detected no further sign of E. coli since then.
However, results from total coliform tests at Waikouaiti on Sunday and Karitane on Wednesday were being investigated to determine the exact type of bacteria found and the associated risk, council group manager Three Waters Tom Dyer said.
He reminded residents the ‘‘do not drink’’ notice remained in place.
The source of the E. coli and total coliform results was still being investigated and testing continued.
Staff and contractors will also be flushing the network over the next few days, which residents in affected communities would see being done over the weekend and early next week.
The council was working with Public Health South on the issue, and both parties needed three days of clear results before being satisfied the water was free of E. coli or coliform bacteria.
