There are "hot spots" around Otago where septic-tank systems may be causing water quality problems, Otago Regional Council resource management director Selva Selvarajah says.
Inspections of septic-tank systems associated with commercial operators in Central Otago showed many were not complying with consent conditions, a recent report to the council's consents committee said.
Issues ranged from basic lack of maintenance and reporting, to very poor effluent quality.
Those consent-holders had been asked to report back to the council on how they planned to upgrade their facilities, it said.
Chairman Stephen Cairns said he was surprised to see that septic tanks were an issue in Central Otago.
"It's an issue around the region and that is not good enough in this day and age."
Dr Selvarajah said there were "hot spots" around the region and in the past there had been some problems with overflow affecting water quality in small communities.
The conditions were not too onerous for commercial enterprises to meet, he said.
The Ministry for the Environment consulted on a proposed national environmental standard for domestic on-site waste water systems last year after concerns many systems did not provide adequate levels of treatment and had an adverse impact on human health and the environment.
A ministry spokeswoman said the standard had been put on hold but was now with the Environment Minister's office and an announcement was expected in the next few weeks.
Mr Cairns said he hoped the announcement would lead to some form of standard being set which would drive awareness of the need for proper maintenance and installation of septic-tank systems.
"I hope it might drive some improvements in existing systems, as you can add to them and make them more efficient."
