Seven Gippsland dairy farms have been hit with fines totalling more than $20,000 for effluent management breaches.
The Environment Protection Authority Victoria found just 15 per cent of farms it inspected in an area of Gippsland were compliant.
The inspections were part of a statewide blitz conducted by the EPA in the past year.
EPA officers visited 19 farms in the Poowong North, Hallora, Nyora, Ripplebrook and Athlone areas.
The EPA said 85 per cent were non-compliant - despite ongoing communications with the dairy industry about effluent management requirements.
"EPA has consistently communicated with dairy farmers about the requirements regarding on farm management of dairy effluent," EPA Gippsland regional manager Jessica Bandiera said.
"To find that just 15 per cent of the farms visited were compliant is surprising and disappointing."
Ms Bandiera said farmers could take many actions to prevent harm to the environment.
"Maintaining a dairy effluent management system is vital," she said.
"Cleaning out the dairy effluent ponds regularly and ensuring appropriate irrigation systems are in place will capture valuable resources and save thousands in fertilizer costs."
Ms Bandiera said nearly half the inspected farms were expected to receive some kind of sanction, and more than two thirds would receive a notice to make specific improvements.
On top of the seven farms fined, a further nine were given compliance advice and issued notices requiring to install controls or complete works to better manage their risks.
"Everyone has to act to protect the environment," Ms Banidera said.
"Dairy effluent cannot be allowed to be discharged to waterways.
"It is high in substances that may be toxic and pose a risk to the environment and human health."
The majority of non-compliance issues concerned dairy effluent ponds that were full or overflowing into paddocks and into waterways, broken or ineffective equipment such as pumps and irrigation systems and not having an effluent management plan in place.
"Some farms even had pipes directly discharging into waterways," Ms Baniera said
"There are assistance schemes, guidance and advice links available through EPA's website, and other agencies EPA works closely with such as Agriculture Victoria.
"This can assist farmers so they can make the necessary improvements, retain valuable nutrients on their farms, and importantly for businesses, save them money while protecting the environment.
"We'll continue with our inspection program and take strong regulatory action if we find non-compliance."
For information about managing dairy effluent go to epa.vic.gov.au/for-business/find-a-topic/effluent-dairy-farm.
Want to read more stories like this?
Sign up below (select Dairy News) to receive our e-newsletter delivered fresh to your email inbox twice a week.