The council's compliance and education manager Rob Dragten said staff had checked water up to 2km downstream from the spill site and had not yet seen ill-effects on aquatic life.
"We're hopeful the spill will have had minimal impact on eels, fish and other stream life but we'd ask the public to be on the lookout and report any signs of problems with aquatic life in the Taiari Stream and Ohinemuri River."
Until the test results are revealed, the Waikato District Health Board advises those in the vicinity to take a precautionary approach and avoid contact with the water.
The Hauraki District Council confirmed there were no risks to public water supplies.