Victoria's clean country air doesn't need monitoring, the state's environmental watchdog says, despite a scathing report revealing it has failed to properly check pollution levels.
An Auditor-General report released on Thursday revealed the Environment Protection Authority was unable to properly detail air quality in 40 well-populated areas including Ballarat, Bendigo, Mildura, Shepparton and Warrnambool.
The EPA is required to monitor air quality in each urban centre with a population of at least 25,000 people, which it failed to do.
Only two of eight regions required to have air monitors were measured.
EPA boss Nial Finegan said the watchdog doesn't monitor some regional areas because it knows the air quality is good.
"We'd be basically measuring good air and saying the air is good," he told 3AW on Friday.
The EPA had accepted all recommendations and has an action plan already in place to implement them, Mr Finegan said.
"We know we need to improve and lift our game."