An Environment Protection Authority internal review of its response to a sewer spill on a farm last year has found the agency acted appropriately.
It also found Gippsland Water self-reported the spill to EPA and "appropriately contained and cleaned up the spill".
However, the review found areas for procedural improvement.
The spill occurred on a farm in Flynn, near Traralgon, in February 2016 from the Rosedale-Traralgon sewerage main which is managed by Gippsland Water, an EPA statement this week said.
It was due to an air valve failure on 1 February, according to the statement.
"The review found that although the incident did not enter the broader environment, the sewage entered a farm dam used for stock watering and the contaminated water was used across the farm via stock watering troughs," the statement read.
The EPA said it launched the internal review following new information it received in May this year that sewage spill caused the farmer significant economic impacts, and that a number of cattle had to be quarantined.
The authority did not attend the spill at the time "after its preliminary assessment determined that the air valve, dam, and watering system had been isolated, the spill had been stopped and clean-up was underway", the statement read.
The review found EPA officers appropriately assessed the initial information provided by Gippsland Water against its triage policy and this information "did not indicate a significant environmental problem or outline the scale and impact of the spill".
It also found EPA provided "appropriate advice to the farmer, as requested, and appropriately recorded their interactions about the incident".
EPA's executive director of regulatory services Damian Wells said while the review found both EPA and Gippsland Water broadly met expectations in response to the incident, it also found a number of areas for improvement.
"Despite EPA guidance clearly indicating expectations on water corporations reporting significant sewer spills, the report from Gippsland Water was delayed and did not meet these timelines or information expectations," Mr Wells said.
"Gippsland Water self-reported the spill to EPA three hours after it was confirmed and while they have no legal obligation to report the spill, EPA guidelines stipulate notifications for spills such as this should be made within 30 minutes.
"The review also found further information could have been sought by the EPA officer from Gippsland Water which may have influenced a different response to the incident, a possible visit to the site and gathering evidence to support an infringement notice."
The review panel's recommendations included amending EPA's triage procedure to reinforce its expectation that officers should make further enquiries of reports being assessed and reinforcing with water corporations the EPA's expectations regarding reporting incidents and follow-up activities.
Gippsland Water's acting managing director Paul Clark said in a statement, the corporation had met all of its regulatory and legal obligations in regard to the clean-up and reporting.
"While we reported within three hours, the guideline asks for 30 minutes which is often difficult to achieve in rural areas due to travel time, and we always do our best to report quickly," Mr Clark said.
"If there is an occasion where, for example, we have a pipe break or a spill our priority is rectify the situation as quickly as possible in the most environmentally sound way possible," he said.
Mr Clark said while Gippsland Water was not legally required to notify the EPA or provide an additional detailed report, it chose to do this "as part of our comprehensive post-incident review".
Gippsland Water said it would continue to work with the EPA to improve its systems and communication.