A statement from the council tonight said that despite initial tests on Wednesday indicating the lake water quality at all sample points was within safe swimming guidelines, further testing yesterday indicated higher bacteria levels at two points near the mouth of the Waiteti Stream.
Additionally, following the heavy rain yesterday and this morning, as per the standard public health warning, people should avoid swimming in lakes, rivers, streams and estuaries for a period of 48 hours after heavy or prolonged rain due to potential bacteria contamination from water runoff, the statement said.
For these reasons the health warning will remain in place over the weekend.
The spill, described by locals as brown water "spraying like a fountain", happened at 7pm on October 18. It is estimated that up to 20cu m of wastewater may have reached the lake over three hours.
Test results showed bacteria levels had not dropped as expected after the weekend, prompting more testing to be done this week.
