Weekly sampling of river water is continuing around the Alexandra wastewater treatment plant, although the area is again open to the public.
Warning signs were installed in the area known as Graveyard Gully last week after a main pipeline at the plant was punctured, causing raw sewage spill out and run down the gully until contractors who were working on site were able to build a dam.
The pipe was mended, the sewage was scraped up and the area was disinfected with chlorine and lime, but investigations were continuing, Central Otago District Council water services manager Russell Bond said.
He said weekly water sampling would continue for the next couple of weeks and incident reports were yet to be completed.
Until those reports were done, it would not be determined who would have to cover the cost of the incident.
The chlorine used would have broken down by now, he said.
"It has quite a short life out in the environment, especially in the sun ...just a matter of days."
The lime used to control odour at the site would have taken "probably longer" to break down.
"But we have had a bit of rain so it could have washed into the soil."
He said it was up to the Otago Regional Council to decide when the weekly river water tests were no longer necessary.
